Calmodulin-binding Protein Research Articles

Deciphering the alteration of MAP2 interactome caused by a schizophrenia-associated phosphorylation

Microtubule-associated protein 2 (MAP2) is a crucial regulator of dendritic structure and neuronal function, orchestrating diverse protein interactions within the microtubule network. We have shown MAP2 is hyperphosphorylated at serine 1782 (S1782) in schizophrenia and phosphomimetic mutation of S1782 in mice (MAP2S1782E) is sufficient to impair dendritic architecture. We sought to determine how this hyperphosphorylation affects the MAP2 interactome to provide insights into the disorder's mechanisms. We investigated the MAP2 interactome using co-immunoprecipitation and mass spectrometry in MAP2S1782E and MAP2WT mice. We found that S1782E MAP2 led to a substantial disruption of protein-protein interactions relative to WT MAP2. Reduced interactions with PDZ domain-containing proteins, calmodulin-binding proteins, ribosome proteins, and kinesin proteins may all contribute to dendritic impairments induced by S1782E, and may be linked to schizophrenia pathogenesis. Interestingly, novel gain-of-function interactions with PPM1L and KLHL8 nominated these as regulators of phosphoS1782 MAP2 abundance and potential therapeutic targets in schizophrenia.

Genome-wide analysis of calmodulin binding Protein60 candidates in the important crop plants.

Efficient management of environmental stresses is essential for sustainable crop production. Calcium (Ca²⁺) signaling plays a crucial role in regulating responses to both biotic and abiotic stresses, particularly during host-pathogen interactions. In Arabidopsis thaliana, calmodulin-binding protein 60 (CBP60) family members, such as AtCBP60g, AtCBP60a, and AtSARD1, have been well characterized for their involvement in immune regulation. However, a comprehensive understanding of CBP60 genes in major crops remains limited. In this study, we utilized the Phytozome v12.1 database to identify and analyze CBP60 genes in agriculturally important crops. Expression patterns of a Oryza sativa (rice) CBP60 gene, OsCBP60bcd-1, were assessed in resistant and susceptible rice genotypes in response to infection by the bacterial pathogen Xanthomonas oryzae. Localization of CBP60 proteins was analyzed to predict their functional roles, and computational promoter analysis was performed to identify stress-responsive cis-regulatory elements. Phylogenetic analysis revealed that most CBP60 genes in crops belong to the immune-related clade. Expression analysis showed that OsCBP60bcd-1 was significantly upregulated in the resistant rice genotype upon pathogen infection. Subcellular localization studies suggested that the majority of CBP60 proteins are nuclear-localized, indicating a potential role as transcription factors. Promoter analysis identified diverse stress-responsive cis-regulatory elements in the promoters of CBP60 genes, highlighting their regulatory potential under stress conditions. The upregulation of OsCBP60bcd-1 in response to Xanthomonas oryzae and the presence of stress-responsive elements in its promoter underscore the importance of CBP60 genes in pathogen defense. These findings provide a basis for further investigation into the functional roles of CBP60 genes in crop disease resistance, with implications for enhancing stress resilience in agricultural species.

BEACH domain-containing protein SPIRRIG facilitates microtubule cytoskeleton-associated trichome morphogenesis in Arabidopsis.

Our studies reveal the involvement of SPI in cytoskeleton-associated trichome morphogenesis, expanding the roles of SPI in regulating plant epidermal celldevelopment. Acquisition of distinct shapes is crucial for cells to perform their biological functions in multicellular organisms. Trichomes are specialized epidermal cells of plant aerial parts, offering an excellent paradigm for dissecting the underlying regulatory mechanism of plant cell shape development at the single-cell level. SPIRRIG (SPI) that encodes a BEACH domain-containing protein was initially identified to regulate trichome branch extension, but the possible pathway(s) through which SPI regulates trichome morphogenesis remain unclear. Here, we report that SPI facilitates microtubule-associated regulation on trichome branching in Arabidopsis. Functional loss of SPI results in trichome morphogenesis hyper-sensitive to the microtubule-disrupting drug oryzalin, implying SPI may mediate microtubule stability during trichome development. Accordingly, spi mutant has less-branched trichomes. Detailed live-cell imaging showed that the spatio-temporal microtubule organization during trichome morphogenesis is aberrant in spi mutants. Further genetic investigation indicated that SPI may cooperate with ZWICHEL (ZWI) to modulate microtubule dynamics during trichome morphogenesis. ZWI encodes a kinesin-like calmodulin-binding protein (KCBP), whose distribution is necessary for the proper microtubule organization in trichomes, and zwi mutants produce less-branched trichomes as well. Trichome branching is further inhibited in spi-3 zwi-101 double mutants compared to either of the single mutant. Moreover, we found SPI could co-localize with the MYTH4 domain of ZWI. Taken together, our results expand the role of SPI in regulating trichome morphogenesis and also reveal a molecular and genetic pathway in plant cell shape formation control.

Identification of quantitative trait loci of pod dehiscence in a collection of soybean grown in the southeast of Kazakhstan.

Soybean [Glycine max (L.) Merr.] is one of the important crops that are constantly increasing their cultivation area in Kazakhstan. It is particularly significant in the southeastern regions of the country, which are currently predominant areas for cultivating this crop. One negative trait reducing yield in these dry areas is pod dehiscence (PD). Therefore, it is essential to understand the genetic control of PD to breed new cultivars with high yield potential. In this study, we evaluated 273 soybean accessions from different regions of the world for PD resistance in the conditions of southeastern regions of Kazakhstan in 2019 and 2021. The field data for PD suggested that 12 accessions were susceptible to PD in both studied years, and 32 accessions, in one of the two studied years. The genotyping of the collection using a DNA marker for the Pdh1 gene, a major gene for PD, revealed that 244 accessions had the homozygous R (resistant) allele, 14 had the homozygous S (susceptible) allele, and 15 accessions showed heterozygosity. To identify additional quantitative trait loci (QTLs), we applied an association mapping study using a 6K SNP Illumina iSelect array. The results suggested that in addition to major QTL on chromosome 16, linked to the physical location of Pdh1, two minor QTLs were identified on chromosomes 10 and 13. Both minor QTLs for PD were associated with calmodulin-binding protein, which presumably plays an important role in regulating PD in dry areas. Thus, the current study provided additional insight into PD regulation in soybean. The identified QTLs for PD can be efficiently employed in breeding for high-yield soybean cultivars.

Can calmodulin bind to lipids of the cytosolic leaflet of plasma membranes?

Calmodulin (CaM) is a ubiquitous calcium-sensitive messenger in eukaryotic cells. It was previously shown that CaM possesses an affinity for diverse lipid moieties, including those found on CaM-binding proteins. These facts, together with our observation that CaM accumulates in membrane-rich protrusions of HeLa cells upon increased cytosolic calcium, motivated us to perform a systematic search for unmediated CaM interactions with model lipid membranes mimicking the cytosolic leaflet of plasma membranes. A range of experimental techniques and molecular dynamics simulations prove unambiguously that CaM interacts with lipid bilayers in the presence of calcium ions. The lipids phosphatidylserine (PS) and phosphatidylethanolamine (PE) hold the key to CaM-membrane interactions. Calcium induces an essential conformational rearrangement of CaM, but calcium binding to the headgroup of PS also neutralizes the membrane negative surface charge. More intriguingly, PE plays a dual role-it not only forms hydrogen bonds with CaM, but also destabilizes the lipid bilayer increasing the exposure of hydrophobic acyl chains to the interacting proteins. Our findings suggest that upon increased intracellular calcium concentration, CaM and the cytosolic leaflet of cellular membranes can be functionally connected.

Distinct profiles of plant immune resilience revealed by natural variation in warm temperature-modulated disease resistance among Arabidopsis accessions.

Elevated temperature suppresses the plant defence hormone salicylic acid (SA) by downregulating the expression of master immune regulatory genes CALMODULIN BINDING PROTEIN 60-LIKE G (CBP60g) and SYSTEMIC ACQUIRED RESISTANCE DEFICIENT1 (SARD1). However, previous studies in Arabidopsis thaliana plants have primarily focused on the accession Columbia-0 (Col-0), while the genetic determinants of intraspecific variation in Arabidopsis immunity under elevated temperature remain unknown. Here we show that BASIC HELIX LOOP HELIX 059 (bHLH059), a thermosensitive SA regulator at nonstress temperatures, does not regulate immune suppression under warmer temperatures. In agreement, temperature-resilient and -sensitive Arabidopsis accessions based on disease resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000 did not correlate with bHLH059 polymorphisms. Instead, we found that temperature-resilient accessions exhibit varying CBP60g and SARD1 expression profiles, potentially revealing CBP60g/SARD1-dependent and independent mechanisms of immune resilience to warming temperature. We identified thermoresilient accessions that exhibited either temperature-sensitive or -insensitive induction of the SA biosynthetic gene ICS1 (direct target gene of CBP60g and SARD1) and SA hormone levels. Collectively, this study has unveiled the intraspecific diversity of Arabidopsis immune responses under warm temperatures, which could aid in predicting plant responses to climate change and provide foundational knowledge for climate-resilient crop engineering.

Combining molecular docking and experimental approaches to uncover how Ca2+/PpCaM1-PpCAMTA3 regulated PpLCD2 expression and hydrogen sulfide production contributing to chilling tolerance in peach fruit

Hydrogen sulfide (H2S) and calcium ions (Ca2+) are implicated in various processes in fruit response to cold. L-cysteine desulfhydrase (LCD) produces H2S using L-cysteine as a substrate, but the exact role of Ca2+ signaling in LCD-mediated H2S synthesis to induce chilling tolerance in peach fruit remains unclear. Here, transcriptome analysis revealed that most differentially expressed genes associated with Ca2+ signaling after H2S treatment function in calcium ion binding and calmodulin (CaM) binding. CaM-binding transcription activator (CAMTA) is a class of CaM-binding proteins and CaM-CAMTA may be a master regulator of fruit response to cold. Further investigation implied that PpCAMTA3 positively regulated PpLCD2 transcription by binding to the CG-box motif via multiple interactions. Three PpCaM genes were identified, in which PpCaM1 interaction with PpCAMTA3 probably occurred through hydrogen bonding with the third IQ domain. Each dumbbell-shaped structure of PpCaM1 contained two EF-hand domains that bound two calcium ions, and the interaction of PpCaM1 and PpCAMTA3 was Ca2+-dependent, enhancing PpCAMTA3-mediated PpLCD2 transcriptional activation. Exogenous H2S further increased intracellular Ca2+ concentrations and PpCaM expression, which resulted in a higher PpLCD2 expression and H2S synthesis, contributing to chilling tolerance in peach fruit. These findings indicated that the Ca2+/PpCaM1-PpCAMTA3 module regulated H2S production in peach fruit under cold stress, thus shedding light on the mechanisms of peach fruit response to cold stress.

Calmodulin‐Based Dynamic Protein Hydrogels with Three Distinct Mechanical Stiffness

AbstractStimuli‐responsive hydrogels that leverage protein conformational changes are of significant interest in the design of dynamic materials applicable in a myriad of fields, such as drug delivery, actuators, biosensors, and microfluidics. The small calcium binding protein calmodulin (CaM), which undergoes three‐stage conformational changes upon successive binding with Ca2+ and specific ligands, offers a mechanism to create dynamic hydrogels with three distinct physical states. In this work, a CaM‐based recombinant protein hydrogel is engineered using [Ru(bpy)3]2+‐mediated photo‐crosslinking. This hydrogel displays the ability to reversibly increase its Young's modulus by 1.5‐fold and ∼7‐fold, respectively, upon binding with Ca2+ and subsequent interaction with trifluoperazine. The magnitude of stiffness changes is tunable by adjusting the length proportion of dynamic and static domains and modifying protein content. This tunable and reversible control over hydrogel mechanics is further utilized to engineer shape‐morphing materials, highlighting the versatile potential of this CaM‐based protein hydrogel for diverse applications.

Genome-Wide Identification of Calmodulin-Binding Protein 60 Gene Family and the Function of GhCBP60B in Cotton Growth and Development and Abiotic Stress Response.

The calmodulin-binding protein 60 (CBP60) family is a gene family unique to plants, and its members play a crucial role in plant defense responses to pathogens and growth and development. Considering that cotton is the primary source of natural cotton textile fiber, the functional study of its CBP60 gene family members is critical. In this research, we successfully identified 162 CBP60 members from the genomes of 21 species. Of these, 72 members were found in four cotton species, divided into four clades. To understand the function of GhCBP60B in cotton in depth, we conducted a detailed analysis of its sequence, structure, cis-acting elements, and expression patterns. Research results show that GhCBP60B is located in the nucleus and plays a crucial role in cotton growth and development and response to salt and drought stress. After using VIGS (virus-induced gene silencing) technology to conduct gene silencing experiments, we found that the plants silenced by GhCBP60B showed dwarf plants and shortened stem nodes, and the expression of related immune genes also changed. In further abiotic stress treatment experiments, we found that GhCBP60B-silenced plants were more sensitive to drought and salt stress, and their POD (peroxidase) activity was also significantly reduced. These results imply the vital role of GhCBP60B in cotton, especially in regulating plant responses to drought and salt stress. This study systematically analyzed CBP60 gene family members through bioinformatics methods and explored in depth the biological function of GhCBP60B in cotton. These research results lay a solid foundation for the future use of the GhCBP60B gene to improve cotton plant type and its drought and salt resistance.

Disruption of Ca2+/calmodulin:KSR1 interaction lowers ERK activation.

KSR1, a key scaffold protein for the MAPK pathway, facilitates ERK activation upon growth factor stimulation. We recently demonstrated that KSR1 binds the Ca2+-binding protein calmodulin (CaM), thereby providing an intersection between KSR1-mediated and Ca2+ signaling. In this study, we set out to generate a KSR1 point mutant with reduced Ca2+/CaM binding in order to unravel the functional implications of their interaction. To do so, we solved the structural determinants of complex formation. Using purified fragments of KSR1, we showed that Ca2+/CaM binds to the CA3 domain of KSR1. We then used in silico molecular modeling to predict contact residues for binding. This approach identified two possible modes of interaction: (1) binding of extended Ca2+/CaM to a globular conformation of KSR1-CA3 via electrostatic interactions or (2) binding of collapsed Ca2+/CaM to α-helical KSR1-CA3 via hydrophobic interactions. Experimentally, site-directed mutagenesis of the predicted contact residues for the two binding models favored that where collapsed Ca2+/CaM binds to the α-helical conformation of KSR1-CA3. Importantly, replacing KSR1-Phe355 with Asp reduces Ca2+/CaM binding by 76%. The KSR1-F355D mutation also significantly impairs the ability of EGF to activate ERK, which reveals that Ca2+/CaM binding promotes KSR1-mediated MAPK signaling. This work, by uncovering structural insight into the binding of KSR1 to Ca2+/CaM, identifies a KSR1 single-point mutant as a bioreagent to selectively study the crosstalk between Ca2+ and KSR1-mediated signaling.

Functional Analysis of the GhIQD1 Gene in Cotton Resistance to Verticillium Wilt.

Cotton is a critical crop with massive economic implications worldwide. Verticillium wilt is a soil-borne ailment caused by Verticillium dahliae, which harms the growth and development of cotton. Therefore, investigating the genes associated with resistance to verticillium wilt is of particular significance. In this study, we identified the GhIQD1 gene through transcriptome analysis and experimentally characterized the role of the GhIQD1 gene in cotton against V. dahliae. The findings indicated that GhIQD1 acts as a calmodulin-binding protein. The expression of GhIQD1 was the highest in stems, and the expression level increased significantly following infection with V. dahliae. The expression in resistant cotton varieties was higher than in susceptible cotton varieties. Through overexpression of the GhIQD1 gene in tobacco, these transgenic plants exhibited improved resistance to V. dahliae. In contrast, by silencing the GhIQD1 gene in cotton through VIGS, the resistance to V. dahliae was reduced. Following inoculation, the leaves yellowed, and the disease index was higher. Transcriptome analysis of transgenic tobacco 72 h after inoculation indicated that overexpression of GhIQD1 increased the enrichment of the calmodulin pathway and stimulated the production of plant hormones alongside secondary metabolites. Consequently, we investigated the relationship between the GhIQD1 gene and plant disease-resistant hormones SA, JA, and ABA. In summary, this study uncovered the mechanism by which GhIQD1 conferred resistance to V. dahliae in cotton through positive regulation of JA and ABA, providing crucial information for further research on the adaptation of plants to pathogen invasion.

Simultaneous Application of Several Exogenous dsRNAs for the Regulation of Anthocyanin Biosynthesis in Arabidopsis thaliana.

Plant surface treatment with double-stranded RNAs (dsRNAs) has gained recognition as a promising method for inducing gene silencing and combating plant pathogens. However, the regulation of endogenous plant genes by external dsRNAs has not been sufficiently investigated. Also, the effect of the simultaneous application of multiple gene-specific dsRNAs has not been analyzed. The aim of this study was to exogenously target five genes in Arabidopsis thaliana, namely, three transcription factor genes (AtCPC, AtMybL2, AtANAC032), a calmodulin-binding protein gene (AtCBP60g), and an anthocyanidin reductase gene (AtBAN), which are known as negative regulators of anthocyanin accumulation. Exogenous dsRNAs encoding these genes were applied to the leaf surface of A. thaliana either individually or in mixtures. The mRNA levels of the five targets were analyzed using qRT-PCR, and anthocyanin content was evaluated through HPLC-MS. The results demonstrated significant downregulation of all five target genes by the exogenous dsRNAs, resulting in enhanced expression of chalcone synthase (AtCHS) gene and increased anthocyanin content. The simultaneous foliar application of the five dsRNAs proved to be more efficient in activating anthocyanin accumulation compared to the application of individual dsRNAs. These findings hold considerable importance in plant biotechnology and gene function studies.

Identification and Molecular Characterization of the CAMTA Gene Family in Solanaceae with a Focus on the Expression Analysis of Eggplant Genes under Cold Stress.

Calmodulin-binding transcription activator (CAMTA) is an important calmodulin-binding protein with a conserved structure in eukaryotes which is widely involved in plant stress response, growth and development, hormone signal transduction, and other biological processes. Although CAMTA genes have been identified and characterized in many plant species, a systematic and comprehensive analysis of CAMTA genes in the Solanaceae genome is performed for the first time in this study. A total of 28 CAMTA genes were identified using bioinformatics tools, and the biochemical/physicochemical properties of these proteins were investigated. CAMTA genes were categorized into three major groups according to phylogenetic analysis. Tissue-expression profiles indicated divergent spatiotemporal expression patterns of SmCAMTAs. Furthermore, transcriptome analysis of SmCAMTA genes showed that exposure to cold induced differential expression of many eggplant CAMTA genes. Yeast two-hybrid and bimolecular fluorescent complementary assays suggested an interaction between SmCAMTA2 and SmERF1, promoting the transcription of the cold key factor SmCBF2, which may be an important mechanism for plant cold resistance. In summary, our results provide essential information for further functional research on Solanaceae family genes, and possibly other plant families, in the determination of the development of plants.

Multiplex gene editing reveals cucumber MILDEW RESISTANCE LOCUS O family roles in powdery mildew resistance.

Powdery mildew (PM) is one of the most widespread and prevalent diseases that affects a wide range of crops. In cucumber (Cucumis sativus L.), previous forward genetic studies have identified MILDEW RESISTANCE LOCUS O 8 (CsMLO8) as necessary but alone insufficient for cucumber PM resistance (PMR) and suggested the involvement of other members of the CsMLO family. However, the function of other CsMLO family members in cucumber remains largely unknown. Here, we developed a highly efficient multiplex gene editing system in cucumber to generate a series of Csmlo mutants from all the 13 family members. Systematic analysis of these mutants revealed growth effects of these CsMLO family members on development and PMR. Importantly, we obtained the Csmlo1/8/11 triple mutant with complete resistance to PM. Transcriptome and proteome analysis of PM-resistant Csmlo mutants suggested that the kinesin-like calmodulin-binding protein (KCBP)-interacting Ca2+-binding protein (CsKIC), calmodulin-like protein 28 (CsCML28), and Ca2+-dependent protein kinase 11 (CsCPK11)-mediated calcium signaling pathway is involved in PMR. CsMLO8 interacted directly with CsKIC, and the simultaneous silencing of both genes resulted in a phenotype that resembled the silencing of CsKIC alone. Silencing CsCML28 and CsCPK11 increased susceptibility to PM, whereas overexpressing CsCPK11 through genetic transformation enhanced cucumber's PMR, demonstrating their positive regulatory roles in PMR. Given the importance of PMR for cucurbit crops, this research provides unprecedented insights into the function of the proteins encoded by the CsMLO gene family as well as the plant defense response to PM pathogen.

The Complex Interplay between Toxic Hallmark Proteins, Calmodulin-Binding Proteins, Ion Channels, and Receptors Involved in Calcium Dyshomeostasis in Neurodegeneration.

Calcium dyshomeostasis is an early critical event in neurodegeneration as exemplified by Alzheimer's (AD), Huntington's (HD) and Parkinson's (PD) diseases. Neuronal calcium homeostasis is maintained by a diversity of ion channels, buffers, calcium-binding protein effectors, and intracellular storage in the endoplasmic reticulum, mitochondria, and lysosomes. The function of these components and compartments is impacted by the toxic hallmark proteins of AD (amyloid beta and Tau), HD (huntingtin) and PD (alpha-synuclein) as well as by interactions with downstream calcium-binding proteins, especially calmodulin. Each of the toxic hallmark proteins (amyloid beta, Tau, huntingtin, and alpha-synuclein) binds to calmodulin. Multiple channels and receptors involved in calcium homeostasis and dysregulation also bind to and are regulated by calmodulin. The primary goal of this review is to show the complexity of these interactions and how they can impact research and the search for therapies. A secondary goal is to suggest that therapeutic targets downstream from calcium dyshomeostasis may offer greater opportunities for success.

The clarithromycin-binding proteins NIPSNAP1 and 2 regulate cytokine production through mitochondrial quality control

The mechanism underlying the anti-inflammatory effect of macrolide antibiotics, such as clarithromycin (CAM), remains to be clarified. The CAM-binding proteins 4-nitrophenylphosphatase domain and non-neuronal synaptosomal associated protein 25 (SNAP25)-like protein homolog (NIPSNAP) 1 and 2 are involved in the immune response and mitochondrial homeostasis. However, the axis between CAM-NIPSNAP-mitochondria and Toll-like receptor (TLR) and their molecular mechanisms remain unknown. In this study, we sought to elucidate the relationship between mitochondrial homeostasis mediated by NIPSNAP1 and 2 and the immunomodulatory effect of CAM. NIPSNAP1 or 2 knockdown (KD) by RNA interference impaired TLR4-mediated interleukin-8 (IL-8) production. Similar impairment was observed upon treatment with mitochondrial function inhibitors. However, IL-8 secretion was not impaired in NIPSNAP1 and 2 individual knockout (KO) and double KO (DKO) cells. Moreover, the oxygen consumption rate (OCR) in mitochondria measured using a flex analyzer was significantly reduced in NIPSNAP1 or 2 KD cells, but not in DKO cells. CAM also dose-dependently reduced the OCR. These results indicate that CAM suppresses the IL-8 production via the mitochondrial quality control regulated by temporary functional inhibition of NIPSNAP1 and 2. Our findings provide new insight into the mechanisms underlying cytokine production, including the TLR-mitochondria axis, and the immunomodulatory effects of macrolides.

CAMTAs, a family of calmodulin-binding transcription factors, are versatile regulators of biotic and abiotic stress responses in plants

Plants, rooted in one place, are constantly subjected to diverse biotic and abiotic stresses that limit their growth and development, resulting in significant crop losses. In response to stresses, plants deploy several integrated signaling networks to rapidly reprogram gene expression thereby altering cellular processes to adapt and survive under unfavorable conditions. Among the key signaling mechanisms that plants use, calcium- and calcium/calmodulin-mediated signal transduction pathways have emerged as one of the ubiquitous players. The calcium-signaling networks include many calcium and calcium/calmodulin-binding transcription factors. In this review, we focus on the functions of a family of highly conserved calcium/calmodulin-binding Transcription Factors (TFs) called calmodulin-binding transcription activators (CAMTAs) in plants. This family of transcription factors was first identified in plants as calmodulin-binding proteins and discovered later in animals. Genetic studies in the model plant Arabidopsis and crop plants such as rice uncovered crucial roles for CAMTAs in modulating plant responses to both biotic and abiotic stresses. Depending on the type of stress, CAMTAs function as either positive or negative regulators for plant growth and stress responses. Arabidopsis CAMTA3 is the most studied member of CAMTA proteins. It modulates the expression of many key genes involved in different hormone signaling pathways and plays a central role in biotic (bacterial, fungal, and viral pathogens) as well as abiotic (cold, drought, salt, and wounding/mechanical) stress responses. Studies with many point, truncated, loss-of-function, and suppressor mutants of CAMTA3 revealed a complex regulation of its function. Here we summarize the advances in the study of the CAMTA family with a focus on CAMTA3. Further, we identify critical gaps in furthering our understanding of the molecular mechanisms by which these TFs function and discuss potential opportunities to engineer them for biotechnological applications to develop stress-resilient crops.

Calcineurin inhibition, cardiovascular consequences, vascular resistance, and potential responses.

To place the consequences of calcineurin inhibition in a cardiovascular context. Literature review coupled with personal encounters. Calcineurin is a calcium-binding and calmodulin-binding protein that is conserved across evolution from yeast to mammals. The enzyme functions as a calcium-dependent, calmodulin-stimulated protein phosphatase. Its role in regulating physiology has largely been elucidated by observing calcineurin inhibition. Calcineurin inhibition transformed organ transplantation from an experiment into a therapy and made much of general immunotherapy possible. The function of this phosphatase and how its inhibition leads to toxicity concern us to this date. Initial research from patients and animal models implicated a panoply of factors contributing to hypertension and vasculopathy. Subsequently, the role of calcineurin in regulating the effective fluid volume, sodium reabsorption, and potassium and hydrogen ion excretion was elucidated by investigating calcineurin inhibition. Understanding the regulatory effects of calcineurin on endothelial and vascular smooth muscle cell function has also made substantial progress. However, precisely how the increase in systemic vascular resistance arises requires further mechanistic research. Calcineurin inhibition continues to save lives; however, options to counteract the negative effects of calcineurin inhibition should be vigorously pursued.

COG3 confers the chilling tolerance to mediate OsFtsH2-D1 module in rice.

The chilling stress induced by the global climate change harms rice production, especially at seedling and booting stage, which feed half the population of the world. Although there are key quantitative trait locus genes identified in the individual stage, few genes have been reported and functioned at both stages. Utilizing chromosome segment substitution lines (CSSLs) and a combination of map-based cloning and phenotypes of the mutants and overexpression lines, we identified the major gene Chilling-tolerance in Geng/japonica rice 3 (COG3) of q chilling-tolerance at the booting and seedling stage 11 (qCTBS11) conferred chilling tolerance at both seedling and booting stages. COG3 was significantly upregulated in Nipponbare under chilling treatment compared with its expression in 93-11. The loss-of-function mutants cog3 showed a reduced chilling tolerance. On the contrary, overexpression enhanced chilling tolerance. Genome evolution and genetic analysis suggested that COG3 may have undergone strong selection in temperate japonica during domestication. COG3, a putative calmodulin-binding protein, physically interacted with OsFtsH2 at chloroplast. In cog3-1, OsFtsH2-mediated D1 degradation was impaired under chilling treatment compared with wild-type. Our results suggest that COG3 is necessary for maintaining OsFtsH2 protease activity to regulate chilling tolerance at the booting and seedling stage.

Oligomerization and aggregation of NAP-22 with several metal ions

Metal ions participate in various biochemical processes such as electron transport chain, gene transcription, and enzymatic reactions. Furthermore, the aggregation promoting effect of several metal ions on neuronal proteins such as prion, tau, Aβ peptide, and α-synuclein, has been reported. NAP-22 (also called BASP1 or CAP-23) is a neuron-enriched calmodulin-binding protein and one of the major proteins in the detergent-resistant membrane microdomain fraction of the neuronal cell membrane. Previously, we showed oligomer formation of NAP-22 in the presence of several phospholipids and fatty acids. In this study, we found the aggregation of NAP-22 by FeCl2, FeCl3, and AlCl3 using native-PAGE. Oligomer or aggregate formation of NAP-22 by ZnCl2 or CuSO4 was shown with SDS-PAGE after cross-linking with glutaraldehyde. Morphological analysis with electron microscopy revealed the formation of large aggregates composed of small annular oligomers in the presence of FeCl3, AlCl3, or CuSO4. In case of FeCl2 or ZnCl2, instead of large aggregates, scattered annular and globular oligomers were observed. Interestingly, metal ion induced aggregation of NAP-22 was inhibited by several coenzymes such as NADP+, NADPH, or thiamine pyrophosphate. Since NAP-22 is highly expressed in the presynaptic region of the synapse, this result suggests the participation of metal ions not only on the protein and membrane dynamics at the presynaptic region, but also on the metabolic regulation though the interaction with coenzymes.