A-kinase Anchoring Protein 13 Research Articles

InDel and CNV within the AKAP13 Gene Revealing Strong Associations with Growth Traits in Goat.

A-kinase-anchoring protein 13 (AKAP13) is a member of the AKAP protein family that has been found to be associated with bone formation. Thus, we investigated the AKAP13 gene as a potential candidate gene for molecular-marker-assisted selection (MAS) in breeding. Our aim was to explore genetic variations (InDel and CNV) within the AKAP13 gene of Shaanbei white cashmere (SBWC) goats and analyze their relationship with growth traits. Ultimately, we identified three InDel loci (16-bp deletion, 15-bp insertion, and 25-bp deletion) and three CNVs, and the 16-bp and 15-bp loci were significantly associated with goat body length (p < 0.05). Both the 16-bp deletion variant and the 15-bp insertion variant facilitated an increase in body length in goats. In addition to this, there was a certain superposition effect between 16-bp and 15-bp loci, although there was no linkage. Additionally, the CNV1 locus was significantly correlated with body height and body length of goats (p < 0.05), and CNV2 was significantly correlated with chest depth, chest circumference, and cannon circumference of goats (p < 0.05). Individuals with gain type showed excellent growth performance. In conclusion, the InDel and CNV loci that we have identified could possibly serve as effective molecular markers in goat breeding, which is very essential for improving efficiency and success of breeding. Moreover, our findings provide a new avenue for further research into the function of the AKAP13 gene.

Analysis of A-kinase Anchoring Protein 13 (AKAP13) in Peri-Ovulatory Oocyte Maturation [A328

INTRODUCTION: Arrest of oocytes at prophase I of meiosis is crucial for fertility and is maintained by Protein Kinase A (PKA). PKA activity is regulated by A-kinase anchoring proteins (AKAPs) that bind the regulatory subunit of PKA to control enzymatic activity. AKAP13 is expressed in oocytes and granulosa cells of humans and mice. Female mice haploinsufficient for Akap13 showed reduced litter sizes. To determine if AKAP13 in oocytes contributes to female reproductive function, we used an oocyte-specific conditional knockout (cKO) to delete Akap13 in the final stages of oocyte growth. METHODS: Oocytes were collected from mice harboring an oocyte-specific conditional knockout of Akap13 mice, with Cre recombinase expression driven by the Zp3 promoter (Zp3-Cre+, Akap13flox/flox). Akap13 DNA and mRNA were assessed by polymerase chain reaction (PCR) and quantitative PCR (qPCR), respectively. Controls were oocytes harvested from Akap13+/flox mice lacking Cre. Oocytes from control or cKO mice were examined for morphology, meiotic resumption, spindle organization, and spindle positioning at metaphase II. RESULTS: Cre-mediated excision of Akap13 DNA in oocytes was confirmed using PCR. Oocyte mRNA levels of Akap13 in cKO mice were reduced by 90% compared to controls. Live-cell imaging revealed no differences in germinal vessel breakdown, polar body emission, or completion of meiosis I in cKO oocytes as compared to controls. Staining of fixed oocytes revealed that metaphase II spindles and chromosome alignment appeared normal in in vitro-matured cKO oocytes. CONCLUSION: These studies suggest that impairment of female fertility in Akap13 haploinsufficient mice is not caused by impairment of oocyte meiotic maturation.

The role of Hippo pathway signaling and A-kinase anchoring protein 13 in primordial follicle activation and inhibition

To determine whether the mechanotransduction and pharmacomanipulation of A-kinase anchoring protein 13 (AKAP13) altered Hippo signaling pathway transcription and growth factors in granulosa cells. Primary ovarian insufficiency is the depletion or dysfunction of primordial ovarian follicles. Invitro activation of ovarian tissue in patients with primary ovarian insufficiency alters the Hippo and phosphatase and tensin homolog/phosphatidylinositol 3-kinase/protein kinase B/forkhead box O3 pathways. A-kinase anchoring protein 13 is found in granulosa cells and may regulate the Hippo pathway via F-actin polymerization resulting in altered nuclear yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif coactivators and Tea domain family (TEAD) transcription factors. Laboratory studies. Translational science laboratory. None. COV434 cells, derived from a primary human granulosa tumor cell line, were studied under different cell density and well stiffness conditions. Cells were transfected with a TEAD-luciferase (TEAD-luc) reporter as well as expression constructs for AKAP13 or AKAP13 mutants and then treated with AKAP13 activators, inhibitors, and follicle-stimulating hormone. TEAD gene activation or inhibition was measured by TEAD-luciferase assays. The messenger ribonucleic acid levels of Hippo pathway signaling molecules, including connective tissue growth factor (CTGF), baculoviral inhibitors of apoptosis repeat-containing 5, Ankyrin repeat domain-containing protein 1, YAP1, and TEAD1, were measured by quantitative real-time polymerase chain reaction. Protein expressions for AKAP13, CTGF, YAP1, and TEAD1 were measured using Western blot. Increased TEAD-luciferase activity and expression of markers for cellular growth were associated with decreased cell density, increased well stiffness, and AKAP13 activator (A02) treatment. Additionally, decreased TEAD-luc activity and expression of markers for cellular growth were associated with AKAP13 inhibitor (A13) treatment, including a reduced expression of the BIRC5 and ANKRD1 (YAP-responsive genes) transcript levels and CTGF protein levels. There were no changes in TEAD-luc with follicle-stimulating hormone treatment, supporting Hippo pathway involvement in the gonadotropin-independent portion of folliculogenesis. These findings suggest that AKAP13 mediates Hippo-regulated changes in granulosa cell growth via mechanotransduction and pharmacomanipulation. The AKAP13 regulation of the Hippo pathway may represent a potential target for regulation of follicle activation.

AKAP13 couples GPCR signaling to mTORC1 inhibition.

The mammalian target of rapamycin complex 1 (mTORC1) senses multiple stimuli to regulate anabolic and catabolic processes. mTORC1 is typically hyperactivated in multiple human diseases such as cancer and type 2 diabetes. Extensive research has focused on signaling pathways that can activate mTORC1 such as growth factors and amino acids. However, less is known about signaling cues that can directly inhibit mTORC1 activity. Here, we identify A-kinase anchoring protein 13 (AKAP13) as an mTORC1 binding protein, and a crucial regulator of mTORC1 inhibition by G-protein coupled receptor (GPCR) signaling. GPCRs paired to Gαs proteins increase cyclic adenosine 3’5’ monophosphate (cAMP) to activate protein kinase A (PKA). Mechanistically, AKAP13 acts as a scaffold for PKA and mTORC1, where PKA inhibits mTORC1 through the phosphorylation of Raptor on Ser 791. Importantly, AKAP13 mediates mTORC1-induced cell proliferation, cell size, and colony formation. AKAP13 expression correlates with mTORC1 activation and overall lung adenocarcinoma patient survival, as well as lung cancer tumor growth in vivo. Our study identifies AKAP13 as an important player in mTORC1 inhibition by GPCRs, and targeting this pathway may be beneficial for human diseases with hyperactivated mTORC1.

A deletion mutation within the goat AKAP13 gene is significantly associated with litter size

A-kinase anchoring protein 13 (AKAP13) is one of the AKAP protein family members, which is correlated with estrogen receptors (ERs) and progesterone receptor (PR) activity. Consequently, the AKAP13 gene is considered to be one of the candidate genes for regulating female fertility. Hence, the objectives of this study were to discover the potential insertion/deletion (indel) variants within the AKAP13 gene and evaluate their associations with litter size of Shaanbei white cashmere goats (SBWC) to screen candidate genes for the molecular marker-assisted selection (MAS). Ultimately, we found the 16-bp deletion of AKAP13 gene which displayed three genotypes (II, ID and DD). However, it was not confirmed to Hardy-Weinberg equilibrium (HWE) in the tested population. Statistical analysis demonstrated that this 16-bp indel locus was significantly associated with litter size in goats (p < 0.05), in which the ID genotype was a key genotype for increasing litter size in goats. Besides, independent χ 2 tests between different genotypes and litter size showed that high-prolific groups had higher frequency of the ‘D’ allele (p < 0.05). Briefly, AKAP13 gene is a candidate gene for improving fertility, and its 16-bp indel locus can be used as a valid DNA molecular marker for the MAS in goat breeding.

A-kinase anchoring protein 13 interacts with the vitamin D receptor to alter vitamin D-dependent gene activation in uterine leiomyoma cells

To determine if A-kinase anchoring protein 13 (AKAP13) interacts with the vitamin D receptor (VDR) to alter vitamin D-dependent signaling in fibroid cells. Uterine leiomyomas (fibroids) are characterized by a fibrotic extracellular matrix and are associated with vitamin D deficiency. Treatment with vitamin D (1,25-dihydroxyvitamin D3) reduces fibroid growth and extracellular matrix gene expression. A-kinase anchoring protein 13 is overexpressed in fibroids and interacts with nuclear hormone receptors, but it is not known whether AKAP13 may interact with the VDR to affect vitamin D signaling in fibroids. Laboratory studies. Translational science laboratory. Human immortalized fibroid or myometrial cells were treated with 1,25-hydroxyvitamin D3 (1,25(OH)2D3) and transfected using expression constructs for AKAP13 or AKAP13 mutants, RhoQL, C3 transferase, or small interfering ribonucleic acids (RNAs). Messenger ribonucleic acid (mRNA) levels of AKAP13, fibromodulin, and versican as measured by quantitative real-time polymerase chain reaction. Glutathione S-transferase-binding assays. Vitamin D-dependent gene activation as measured by luciferase assays. 1,25(OH)2D3 resulted in a significant reduction in mRNA levels encoding AKAP13, versican, and fibromodulin. Small interfering RNA silencing of AKAP13 decreased both fibromodulin and versican mRNA levels. Glutathione S-transferase-binding assays revealed that AKAP13 bound to the VDR through its nuclear receptor interacting region. Cotransfection of AKAP13 and VDR significantly reduced vitamin D-dependent gene activation. RhoA pathway inhibition partially relieved repression of vitamin D-dependent gene activation by AKAP13. These data suggest that AKAP13 inhibited the vitamin D receptor activation by a mechanism that required, at least in part, RhoA activation.

Long Non-Coding RNA ZNF667-AS1 Knockdown Curbs Liver Metastasis in Acute Myeloid Leukemia by Regulating the microRNA-206/AKAP13 Axis.

BackgroundZinc finger protein 667-antisense RNA 1 (ZNF667-AS1), a long non-coding RNA (lncRNA), plays important parts in tumorigenesis and development of esophageal squamous cell carcinoma, but its function in acute myeloid leukemia (AML) is unknown. Our goal here was to probe the functional mechanism of ZNF667-AS1 in AML by mediating microRNA-206 (miR-206)/A-kinase anchoring protein 13 (AKAP13) axis.Materials and MethodsThe bone marrow samples from AML patients and controls were selected for microarray analysis to select significantly upregulated lncRNAs. Next, effects of ZNF667-AS1 on cell aggressiveness of AML were assessed after delivery of cells with siRNA against ZNF667-AS1. Subcellular fractionation location assay and FISH experiments were used to determine ZNF667-AS1 localization in cells. Dual-luciferase experiments detect the targeting relationships among ZNF667-AS1, miR-206 and AKAP13. Finally, tumor growth and metastasis were evaluated in vivo to determine the relevance of ZNF667-AS1/miR-206/AKAP13 axis.ResultsThe expression of ZNF667-AS1 was upregulated in AML patients, which predicted poor prognosis. Downregulation of ZNF667-AS1 reduced cell proliferation, invasion, tumorigenesis and metastasis. miR-206 inhibitor reversed the repressive role of ZNF667-AS1 knockdown in cell proliferation, invasion and tumorigenesis, while AKAP13 silencing flattened the stimulative role of miR-206 inhibitor in AML malignant aggressiveness. Mechanistically, we demonstrated that ZNF667-AS1 functioned as a molecular sponge for miR-206. In addition, we observed that Wnt/β-catenin pathway was suppressed by ZNF667-AS1 knockdown.ConclusionZNF667-AS1 potentiated AML progression by targeting the miR-206/AKAP13 axis. This indicates ZNF667-AS1 inhibition may act as a prospective therapeutic option for the treatment of AML.

A-Kinase Anchoring Protein 13 (AKAP13) Augments Progesterone Signaling in Uterine Fibroid Cells

Uterine leiomyomata (fibroids) are prevalent sex hormone‒dependent tumors with an altered response to mechanical stress. Ulipristal acetate, a selective progesterone receptor (PR) modulator, significantly reduces fibroid size in patients. However, PR signaling in fibroids and its relationship to mechanical signaling are incompletely understood. Our prior studies revealed that A-kinase anchoring protein 13 (AKAP13) was overexpressed in fibroids and contributed to altered mechanotransduction in fibroids. Because AKAP13 augmented nuclear receptor signaling in other tissues, we sought to determine whether AKAP13 might influence PR signaling in fibroids. Fibroid samples from patients treated with ulipristal acetate or placebo were examined for AKAP13 expression by using immunohistochemistry. In immortalized uterine fibroid cell lines and COS-7 cells, we observed that AKAP13 increased ligand-dependent PR activation of luciferase reporters and endogenous progesterone-responsive genes for PR-B but not PR-A. Inhibition of ERK reduced activation of PR-dependent signaling by AKAP13, but inhibition of p38 MAPK had no effect. In addition, glutathione S-transferase‒binding assays revealed that AKAP13 was bound to PR-B through its carboxyl terminus. These data suggest an intersection of mechanical signaling and PR signaling involving AKAP13 through ERK. Further elucidation of the integration of mechanical and hormonal signaling pathways in fibroids may provide insight into fibroid development and suggest new therapeutic strategies for treatment.

FSH signaling in human granulosa cells is augmented by the PKA regulatory II subunit and Rho-GEF binding regions of a-kinase anchoring protein 13 (AKAP13)

FSH signaling in human granulosa cells is augmented by the PKA regulatory II subunit and Rho-GEF binding regions of a-kinase anchoring protein 13 (AKAP13)

Mice deficient in AKAP13 (BRX) develop compulsive-like behavior and increased body weight

ObjectiveHormonal contributions to the sex-dependent development of both obsessive-compulsive disorder (OCD) and obesity have been described, but the underlying mechanisms are incompletely understood. A-kinase anchoring protein 13 (AKAP13) significantly augments ligand-dependent activation of estrogen receptors alpha and beta. The hypothalamus and pituitary gland are implicated in the development and exacerbation of OCD and obesity and have strong AKAP13 expression. The AKAP13 localization pattern observed in these key brain regions together with its effects on sex steroid action suggest a potential role for AKAP13 in compulsive-like behaviors. Here we tested the role of AKAP13 in compulsive-like behavior and body weight using an Akap13 haploinsufficient murine model. Materials and methodsTargeted deletion of the Akap13 gene generated haploinsufficient (Akap13+/−) mice in a C57BL6/J genetic background. Established behavioral assays were conducted, video recorded, and scored blindly to assess compulsive-like behavior based on genotype and gender. Tests included: marble-burying, grooming, open- field and elevated plus-maze. Brain and body weights were also obtained. Mean levels of test outcomes were compared using multi-way ANOVA to test for genotype, sex, genotype*sex, and genotype*sex*age interaction effects with Bonferroni adjustment for multiple comparisons, to further explain any significant interactions. ResultsThe marble-burying and grooming assays revealed significant sex-dependent increases in perseverative, compulsive-like behaviors in female Akap13 haploinsufficient mice compared to female wild type (WT) mice by demonstrating increased marble-burying activity (p = .0025) and a trend towards increased grooming behavior (p = .06). Male Akap13 haploinsufficient mice exhibited no behavioral changes (p > 0.05). Elevated plus-maze and open-field test results showed no overt anxiety-like behavior in Akap13 haploinsufficient mice irrespective of sex (p > 0.05, both). No differences in brain weight were found in Akap13 haploinsufficient mice compared to WT mice (p > 0.05). However, female Akap13 haploinsufficient mice weighed more than female WT mice in the 4 to <7 months age range (p = .0051). Male Akap13 haploinsufficient mice showed no differences in weight compared to male WT mice (p = >0.05) at any age range examined. ConclusionAkap13 haploinsufficiency led to sex-dependent, compulsive-like behavioral changes in a murine model. Interestingly, Akap13 haploinsufficiency also led to a sex-dependent increase in body weight. These results revealed a requirement for AKAP13 in murine behavior, particularly in female mice, and is the first report of AKAP13 involvement in murine behavior. Future studies may examine the involvement of AKAP13 in the pathophysiology of OCD in female humans and may contribute to a better understanding of the role of AKAP13 and sex hormones in the development and exacerbation of OCD.

The role of a kinase anchoring protein 13 (AKAP13) in ovarian hippo signaling

Recent reports have suggested that ovarian follicle activation could be achieved through disruption of Hippo signaling in the ovary by mechanical signaling (Hsueh et al. Endocr Rev 2015), possibly opening new therapeutic options; however, the mechanism(s) involved are incompletely understood. In stem cells, AKAP13 regulates the key Hippo targets YAP/TAZ by promoting stress fiber formation (Ohgushi et al. Cell Stem Cell 2015). Here we sought to explore whether AKAP13 was required for Hippo signaling in the ovary using conditional deletion of the Akap13 gene targeted to murine granulosa cells.

Vitamin D reduces a kinase anchoring protein 13 (AKAP13) mRNA expression in fibroid cells

Vitamin D deficiency may play a key role in fibroid disease pathogenesis. Not only are African American more likely to be Vitamin D deficient, but they also suffer from a disproportionate fibroid disease burden compared to Caucasian women. Fibroids are characterized by abundant deposition of stiff and disorganized extracellular matrix (ECM). Increased mechanical stress promotes tumorigenesis through activation of the RhoA signaling pathway. We have previously reported that AKAP13, a guanine nucleotide exchange factor for RhoA, was overexpressed in fibroid cells and involved in mechanical signaling.

A-Kinase anchoring protein-13 (AKAP13) may be required for protein kinase A (PKA)-mediated aromatase Expression in granulosa cells

Cyclic AMP (cAMP) is the main intracellular messenger mediating follicle stimulating hormone (FSH) stimulation of aromatase expression in granulosa cells (GCs). An intact PKA pathway in GCs is critical for peak gonadotropin signaling. We have previously shown that AKAP13 is necessary for optimal gonadotropin signaling through cAMP response element binding protein and that both FSH-dependent induction of aromatase and basal aromatase message is decreased with knockdown of AKAP13 in ovaries of AKAP13 conditional knockout mice and in a granulosa cell tumor cell line.

The Rho guanine nucleotide exchange factor (Rho-GEF) domain of a-kinase anchoring protein-13 (AKAP13) is necessary for optimal gonadotropin signaling in granulosa cells

AKAP13 plays an active role in gonadotropin-dependent gene transcription. We previously showed that AKAP13 augments cyclic AMP response element binding protein (CREB) activation in granulosa cells (GCs) and is required for optimal follicle stimulating hormone signaling. Since the exact mechanisms by which AKAP13 mediates gonadotropin signaling through CREB remains unclear, we sought to further explore regions of AKAP13 required for CREB activation.

Anxiety related phenotypes in a-kinase anchoring protein 13 (AKAP13) mice: a potential model for obsessive- compulsive disorder

Brain neurotransmitters are modulated by estrogen; additionally, estrogen has been shown to influence cognitive function, anxiety, and compulsive behavior. Furthermore, recent reports demonstrate a correlation between reduced estrogen levels and the onset of Obsessive-Compulsive Disorder, or exacerbation of pre-existing Obsessive-Compulsive Disorder. Previous research has shown that AKAP13 augments estrogen receptor action by binding to estrogen receptors alpha and beta and is present in the brain.

Structural Insights into the Activation of the RhoA GTPase by the Lymphoid Blast Crisis (Lbc) Oncoprotein

The small GTPase RhoA promotes deregulated signaling upon interaction with lymphoid blast crisis (Lbc), the oncogenic form of A-kinase anchoring protein 13 (AKAP13). The onco-Lbc protein is a hyperactive Rho-specific guanine nucleotide exchange factor (GEF), but its structural mechanism has not been reported despite its involvement in cardiac hypertrophy and cancer causation. The pleckstrin homology (PH) domain of Lbc is located at the C-terminal end of the protein and is shown here to specifically recognize activated RhoA rather than lipids. The isolated dbl homology (DH) domain can function as an independent activator with an enhanced activity. However, the DH domain normally does not act as a solitary Lbc interface with RhoA-GDP. Instead it is negatively controlled by the PH domain. In particular, the DH helical bundle is coupled to the structurally dependent PH domain through a helical linker, which reduces its activity. Together the two domains form a rigid scaffold in solution as evidenced by small angle x-ray scattering and (1)H,(13)C,(15)N-based NMR spectroscopy. The two domains assume a "chair" shape with its back possessing independent GEF activity and the PH domain providing a broad seat for RhoA-GTP docking rather than membrane recognition. This provides structural and dynamical insights into how DH and PH domains work together in solution to support regulated RhoA activity. Mutational analysis supports the bifunctional PH domain mediation of DH-RhoA interactions and explains why the tandem domain is required for controlled GEF signaling.

Tissue-specific knockout of A-kinase anchoring protein 13 (AKAP13) – a potential murine model for polycystic ovarian syndrome

We previously reported that AKAP13 was induced during ovarian follicle growth and that knockdown of akap13 impaired basal aromatase expression and FSH–induced LH receptor expression in murine granulosa cells. AKAP13 binds the regulatory subunit of protein kinase A (PKA), which mediates gonadotropin action in the ovary. Given its implications for folliculogenesis and ovulation, we set out to assess the in vivo role of AKAP13 in murine ovary.