Keratin-associated Proteins Research Articles

Differential expression of keratin and keratin associated proteins are linked with hair loss condition in spontaneously mutated inbred mice

Hair loss condition is heritable and is influenced by multifactorial inheritance. In the present study, spontaneously mutated mice showed hair loss phenotype with defect in the first cycle of hair follicle formation leading to cyclic alopecia. These mutant mice follow autosomal recessive inheritance pattern. The transcriptomic profile and differential gene expression analysis of skin tissues by RNA-sequencing at different stages of hair cycle formation was performed. The genes with significant differential genes expression levels in each stage of hair cycle formation were identified and most of these genes were shown to be associated with keratinization process and hair follicle formation. Transcriptome profiling followed by QPCR validation revealed that mRNA levels of Krt16, Alox15, Fetub (upregulated) and Msx2 (downregulated) were significantly differentially expressed in mutant skin tissues during late anagen and catagen stages. Krt6b mRNA and protein levels were significantly higher in the mutant mice during all stages of first hair cycle formation. The present study provides basis for understanding the differential gene expression of hair-related genes, including keratinization-associated proteins and its relevance. These mutant mice can serve as a model for studying hair loss condition that can be further used in the identification, evaluation and treatment strategies for alopecia condition.

Genetics of Wool and Cashmere Fibre: Progress, Challenges, and Future Research.

Wool (sheep) and cashmere (goat) fibres have unique biological, physical, and chemical properties and these fibres are becoming more important as the demand for natural products increases. However, these complex protein fibres are at times compromised by natural variability in their properties, and this can impact their use and value. Genetic improvement via selection and breeding can partly overcome this problem, enabling the farming of sheep and goats that produce more desirable fibre. This review explores the challenges in improving wool and cashmere fibre characteristics using genetics, with a focus on improving our understanding of the key protein components of fibres, wool keratins and keratin-associated proteins (KAPs). Despite progress in our knowledge of these proteins, gaining a better understanding of them and how they affect these fibres remains an ongoing challenge. This is not straight-forward, given the large number of similar yet unique genes that produce the proteins and the gaps that remain in their identification and characterisation. More research is required to clarify gene and protein sequence variability and the location and patterns of gene expression, which in turn limits our understanding of fibre growth and variation. Several aspects that currently hinder our progress in this quest include the incomplete identification of all the genes and weaknesses in the approaches used to characterise them, including newer omics technologies. We describe future research directions and challenges, including the need for ongoing gene identification, variation characterisation, and gene expression analysis and association studies to enable further improvement to these valuable natural fibres.

Insights into structural and proteomic alterations related to pH-induced changes and protein deamidation in hair.

The hair shaft is often exposed to shampoo and haircare products that have unknown or varying pH levels. These products contain a combination of surfactants and other active ingredients to treat the hair or the scalp. As amphoteric proteins, hair keratins have limited buffering capacity, so variations in pH can have multifaceted impacts on them. However, there is limited knowledge about how pH affects keratins and keratin-associated proteins (KAPs). Therefore, this study aims to examine the effects of varying pH levels (pH 3-pH 12) on hair structure and analyse consequent alterations in the hair proteome using mass spectrometry-based proteomics. A scanning electron microscope was used to examine changes in hair-shaft morphology due to exposure to various pH levels, while mass spectrometry was employed to analyse protein alterations. We found that exposing the hair shaft to varying pH levels led to specific effects on the cuticle, including cuticle lifting at certain pH levels, while proteomics analysis identified alterations in the hair proteome along with significant deamidation of keratins types I and II and KAPs. More pronounced effects were observed at extreme acidic conditions (pH 3) and alkaline conditions (above pH 8) on both hair morphology and hair proteins. pH levels between pH 5 and pH 7 had minimal impact on hair structure and proteins, suggesting that haircare products with pH in this range are ideal for hair-shaft health. In contrast, alkaline pH levels were found to negatively affect hair. The structure evaluation and proteomics data emphasize the critical role of pH in hair health. The extreme acidic or alkaline pH impacts the hair structure and hair proteins. The study highlights the optimal pH range for maintaining healthy hair.

Proteomic Analysis of Crimped and Straight Wool in Chinese Tan Sheep.

Crimped wool in Tan sheep gradually transitions to straight wool after 35 days (the er-mao stage), which reduces its commercial value. To investigate the changes in wool proteins during this stage, we performed comparative proteomic analysis of the straight and crimped wool using tandem mass tag (TMT)-based quantification. The mean fur curvature (MFC) of crimped wool was significantly greater than that of straight wool (p < 0.001). We identified 1218 proteins between the two types of wool, including 50 keratins (Ks) and 10 keratin-associated proteins (KAPs). There were 213 differentially expressed proteins, including 13 Ks and 4 KAPs. Crimped wool showed relatively high abundances of KAP24-1, K84, K32, K82, and intermediate filament rod domain-containing protein (IRDC), whereas straight wool had relatively high abundances of K6A, K27, K80, KAP16-1, KAP27-1, and trichohyalin (TCHH). The expression levels of KAP16-1, KAP24-1, and KAP27-1 were related to the ratio of paracortex, which may be associated with wool crimp formation. Additionally, high expressions of TCHH, K27, and K6A in the inner root sheath (IRS) were linked to fiber fineness in straight wool. These findings provide insight into the overall expression and distribution patterns of Ks and KAPs, offering opportunities to improve wool quality and enhance its economic potential in the textile industry.

Development of a Combined Protein and Dye Extraction Approach for the Analysis of Keratin-Based Textiles.

Archaeological textiles represent precious remains from ancient culture; this is because of the historical and cultural importance of the information that can be obtained by such relics. However, the extremely complicated state of preservation of these textiles, which can be charred, partially or totally mineralized, with heavy soil or biological contamination, requires highly specialized and sensitive analytical tools to perform a comprehensive study. Starting from these considerations, the paper presents a combined workflow that provides the extraction of dyes and keratins and keratin-associated proteins in a single step, minimizing sampling while maximizing the amount of information gained. In the first phase, different approaches were tested and two different protocols were found suitable for the purpose of the unique workflow for dyes/keratin-proteins: a slightly modified urea protocol and a recently proposed new TCEP/CAA procedure. In the second step, after the extraction, different methods of cleanup and workflow for proteins and dyes were investigated to develop protocols that did not result in a loss of aliquots of the analytes of interest and to maximize the recovery of both components from the extracting solution. These protocols investigated the application of two types of paramagnetic beads, unmodified and carboxylate-coated hydrophilic magnetic beads, and dialysis and stage-tip protocols. The newly designed protocols have been applied to cochineal, weld, orchil, kermes, and indigo keratin-based dyed samples to evaluate the effectiveness of the protocols on several dye sources. These protocols, based on a single extraction step, show the possibility of investigating dyes and keratins from a unique sample of 1 mg or lesser, with respect to the thresholds of sensitivity and accuracy required in the study of textile artifacts of historical and artistic values.

Low-Dose Metformin and Profibrotic Signature in Central Centrifugal Cicatricial Alopecia

Central centrifugal cicatricial alopecia (CCCA) is a scarring alopecia predominantly affecting Black female individuals. Current conventional treatments target inflammation but not the underlying fibrotic processes, often leading to permanent hair loss. To investigate the associations of low-dose oral metformin, an antidiabetic medication with antifibrotic properties, with clinical symptoms and scalp gene expression patterns in patients with CCCA. This retrospective clinical case series and transcriptomic analysis included patients treated at a single tertiary academic medical center between January 2023 and March 2024. All patients had biopsy-confirmed CCCA refractory to standard treatments. Transcriptomic analysis was performed on patients with previously banked, paired scalp biopsies before and after treatment with adjuvant metformin for at least 6 weeks. Extended-release metformin, 500 mg, once daily was added to participants' baseline CCCA treatment regimens. Clinical assessments included pruritus, inflammation, scalp resistance, and hair regrowth. Gene expression profiling via bulk RNA sequencing analysis evaluated differential gene expression and pathway enrichment. A total of 12 Black female participants were included in the study, and transcriptomic analysis was performed in 4 participants. After at least 6 months of metformin treatment, 9 participants experienced improvement in disease, including scalp pain, inflammation, and/or pruritus, and 6 demonstrated clinical evidence of hair regrowth. The addition of metformin led to reversal of many prominent gene pathways previously identified in CCCA. Transcriptomic analysis revealed upregulation of pathways and genes (keratin-associated proteins [KRTAPs]) involved in keratinization, epidermis development, and the hair cycle (absolute log2-fold change > 4), with concomitant downregulation of fibrosis-related pathways and genes (eg, MMP7, COL6A1) (fold change >1.5; all false discovery rate <.05). Gene set analysis showed reduced expression of helper T cell 17 and epithelial-mesenchymal transition pathways and elevated adenosine monophosphate kinase signaling and KRTAPs after metformin treatment. In this case series of patients with treatment-refractory CCCA, low-dose oral metformin was associated with symptomatic improvement and dual modulation of gene expression, stimulating hair growth pathways while suppressing fibrosis and inflammation markers. These findings provide a rationale for future clinical trials studying metformin as a targeted therapy for CCCA and other cicatricial alopecias.

Mutation of KAP, which encodes a keratin-associated protein, affects grain size and yield production in rice.

Grain size and shape are critical agronomic traits that directly impact rice grain yield. Identifying genes that control these traits can provide new strategies for yield improvement. In this study, we characterized a rice mutant, reduced grain length (rgl), which exhibited decreased grain length due to reduced cell proliferation. Map-based cloning identified a base deletion in OsRGL2, a gene encoding a keratin-associated protein (KAP), as the cause of the mutant phenotype. CRISPR-Cas9-generated OsRGL2 knockout mutants also displayed reduced grain length, confirming its role. OsRGL2 transcripts were detected in various tissues, with relative higher gene expression in young panicles, and OsRGL2 was localized to the plasma membrane. Overexpression of OsRGL2 increased grain size by promoting cell proliferation in the spikelet hull and significantly enhanced grain yield per plant. Importantly, OsRGL2 was found to interact with RGB1, indicating that OsRGL2 positively regulates grain size and yield through its interaction with RGB1. Additionally, OsRGL2 regulated the expression of cell cycle-related genes, further elucidating its role in grain development. These findings demonstrate that OsRGL2 is a positive regulator of grain size in rice, and manipulating its expression may offer a novel strategy for enhancing rice grain yield.

Effects of KRTAP20-1 Gene Variation on Wool Traits in Chinese Tan Sheep.

Chinese Tan sheep lambs are recognised for having tight 'spring-like' curly wool when young, but this phenotype disappears with age. This wool consists of shorter, fine wool fibres (which are usually unmedullated) and heterotypic hair fibres (which are frequently medullated), which are referred to as 'halo hair'. Both the wool and hair fibres consist of α-keratin proteins embedded in a keratin-associated protein (KAP) matrix. Of these KAPs, the KAP20-1 gene (designated KRTAP20-1) and its effect on four fibre traits (mean fibre curvature, mean fibre diameter, fibre diameter standard deviation, and coefficient of variation of fibre diameter) of Tan lambs was studied. Seven previously identified KRTAP20-1 variants (A, B, D, E, F, G, and H) of KRTAP20-1 were revealed, but the previously identified variant C was not present. Of the seven variants detected, only two (A and G) were common and present at frequencies greater than 5%, and the effect of these on the fibre traits of the finer wool fibres was assessed. It was found that variant G was associated with an increased mean fibre curvature in these wool fibres. This suggests that KRTAP20-1 might possibly be expressed differentially in the two fibre types, which may be of future value in breeding.

Exploring Variation in Ovine KRTAP19-5 and Its Effect on Fine Wool Fibre Curvature in Chinese Tan Sheep.

Sheep's wool is known to have unique biological, physical and chemical properties. The fibre primarily consists of proteins, but these have amino acid sequence variation, and at the phenotypic level wool fibre varies considerably. This can affect its utility and value. Unravelling the genetic factors that underpin the protein and phenotypic variability is crucial if we are to contemplate improving wool quality. Accordingly, this study investigates the high glycine and tyrosine content keratin-associated protein 19-5 gene (KRTAP19-5) in sheep. PCR-single strand confirmation polymorphism analysis, coupled with DNA sequencing of a region spanning whole coding sequence, revealed six sequence variants containing seven single nucleotide polymorphisms (SNPs). Five of the SNPs were located within the coding region, with four leading to amino acid changes if expressed. In 247 Chinese Tan sheep derived from 10 sire-lines, and renowned for their distinct 'spring-like' crimped wool at up to approximately 35 days after birth, one of the variants was found to be associated with decreased curvature of the fine wool fibres in the fleece. No associations were detected with other fibre traits or with variation in the heterotypic hair fibres of the Tan sheep. While these findings may be useful for developing gene markers to alter mean wool fibre curvature and improve sheep breeding, many other genes and environmental factors are known to contribute to variation in fibre traits.

Atomistic Characterization of Healthy and Damaged Hair Surfaces: A Molecular Dynamics Simulation Study of Fatty Acids on Protein Layer.

Amid the bourgeoning demand for in-silico designed, environmentally sustainable, and highly effective hair care formulations, a growing interest is evident in the exploration of realistic computational model for the hair surface. In this work, we present an atomistic model for the outermost layer of the hair surface derived through molecular dynamics simulations, which comprises 18-Methyleicosanoic acid (18-MEA) fatty acid chains covalently bound onto the keratin-associated protein 10-4 (KAP10-4) at a spacing distance of ~1 nm. Remarkably, this hair surface model facilitates the inclusion of free fatty acids (free 18-MEA) into the gaps between chemically bound 18-MEA chains, up to a maximum number that results in a packing density of 0.22 nm2 per fatty acid molecule, consistent with the optimal spacing identified through free energy analysis. Atomistic insights are provided for the organization of fatty acid chains, structural features, and interaction energies on protein-inclusive hair surface models with varying amounts of free 18-MEA (FMEA) depletion, as well as varying degrees of anionic cysteic acid from damaged bound 18-MEA (BMEA), under both dry and wet conditions. In the presence of FMEA and water, the fatty acid chains in a pristine hair surface prefers to adopt a thermodynamically favored extended chain conformation, forming a thicker protective layer (~3 nm) on the protein surface. Our simulation results reveal that, while the depletion of FMEA can induce a pronounced impact on the thickness, tilt angle, and order parameters of fatty acid chains, the removal of BMEA has a marked effect on water penetration. There is a "sweet spot" spacing between the 18-MEA whereby damaged hair surface properties can be reinstated by replenishing FMEA. Through the incorporation of the protein layer and free fatty acids, the hair surface models presented in this study enables a realistic representation of the intricate details within the hair epicuticle, facilitating a molecular scale assessment of surface properties during the formulation design process.

A methodological exploration of distinguishing hair quality based on hair proteomics

Hair is an advantageous biological sample due to its recordable, collectable, and storable nature. Hair's primary components are keratin and keratin-associated proteins. Owing to its abundance of cystine, keratin possesses impressive mechanical strength and chemical stability, formed by creating disulfide bonds as crosslinks within the protein peptide chain. Furthermore, keratin is cross-linked with keratin-associated proteins to create a complex network structure that provides the hair with strength and rigidity. Protein extraction serves as the foundation for hair analysis research. Bleaching hair causes damage to the structure between keratin and keratin-associated proteins, resulting in texture issues and hair breakage. This article outlines various physical treatment methods and lysate analysis that enhance the efficiency of hair protein extraction. The PLEE method achieves a three-fold increase in hair protein extraction efficiency when using a lysis solution containing SDS and combining high temperatures with intense shaking, compared to previous methods found in literature. We utilized the PLEE method to extract hair from both normal and damaged groups. Normal samples identified 156–157 proteins, including 51 keratin and keratin-associated proteins. The damaged group consisted of 155–158 identified proteins, of which 48–50 were keratin and keratin-associated proteins. Bleaching did not cause any notable difference in the protein identification of hair. However, it did reduce coverage of keratin and keratin-associated proteins significantly. Our hair protein extraction method provides extensive coverage of the hair proteome. Our findings indicate that bleaching damage results in subpar hair quality due to reduced coverage of protein primary sequences in keratin and keratin-associated proteins.

Biological Function of Keratin-Associated Protein 26.1 of Liaoning Cashmere Goat Gene Family

Biological Function of Keratin-Associated Protein 26.1 of Liaoning Cashmere Goat Gene Family

Співвідношення структурних протеїнів у вовні овець різних порід та з різною категорією волокон залежно від зон їх розведення

Wool fiber consists of a complex of protein-keratins, which differ in both their physical and chemical properties and functional characteristics. Despite the progress achieved in the study of the structural organization of fibers, the issue of the influence of environmental factors, the nature and level of nutrition, as well as breed characteristics, remains poorly understood. With this in mind, we investigated the ratio of structural proteins in the wool of sheep of different breeds, which are bred in separate zones of Ukraine, in particular, fine-wool, semi-fine-wool, and coarse-wool. Therefore, during the study of the structural proteins of the wool of sheep of different breeds, which differ among themselves in the thinness of the fibers, it was established that by the method of electrophoretic separation, these proteins are clearly divided into three different groups, in particular, these are proteins of intermediate filaments (IF) of I and II types with a molecular weight of 55–65 and 45–55 kDa, respectively, as well as keratin-associated proteins (KAP) with a molecular weight of 25–35 kDa. However, in some breeds, in particular, the Askanian meat-wool of the black-headed type and the Ukrainian Mountain Carpathian type, two more fractions of proteins were found among IF type I, which almost do not differ from each other in terms of percentage. It was established that within the studied groups of sheep, certain interbreed features are observed, so in the group of thin-wooled breeds, the largest percentage falls on IF II (35.9%). The other two factions account for almost the same percentage — 32.1% (IF I) and 31.8% (KAP). An almost similar picture of the ratio of protein fractions was recorded in the group of animals with coarse wool. At the same time, in the group of sheep with semi-fine wool, in particular, the fibers of sheep of the Ascanian meat-wool breed have the highest percentage of KAP and, accordingly, less IF II, and in the fibers of the Ascanian meat-wool black-headed type, respectively, less proteins of IF II and KAP. Therefore, the obtained data clearly indicate breed characteristics of the content and ratios of certain groups of proteins, which can be genetically determined, and therefore serve as appropriate markers both within individual breeds and within breeds with different fiber categories.

Global gene expression profile of proliferative verrucous leukoplakia and its underlying biological disease mechanisms

BackgroundProliferative verrucous leukoplakia (PVL) is a rare and enigmatic oral potentially malignant disorder which almost invariably results in oral squamous cell carcinoma (OSCC). The aims of this project were to use transcriptome profiling to characterise PVL gene expression patterns for biomarker identification and gain insight into the molecular aetiopathogenesis of PVL. MethodsForty-three oral cavity mucosal biopsies from 32 patients with oral lesions clinically compatible with either PVL or non-PVL conventional oral leukoplakia (OLK) underwent transcriptome profiling by RNA sequencing. Data was analysed by hierarchical clustering, differential gene expression, functional enrichment and network analysis, sparse partial least squares discriminant analysis sPLS-DA, and immune cell phenotypic estimation. ResultsWe found 464 genes significantly differentially expressed at least 2-fold between PVL and non-PVL OLK (193 up and 271 down). HOX genes, including HOXA1 and HOXB7, keratin-associated proteins (KRTAPs) and olfactory receptor G proteins (OR) were significantly upregulated in PVL. Other upregulated genes in PVL included FOS, WNT16 and IFNA1. Pathway analysis showed that there was a significant downregulation of connective tissue signalling in PVL. Classifying multivariate models based upon 22 genes discriminated PVL from non-PVL OLK. Bioinformatic profiling showed that immune cell profiles in PVL and OLK were similar except that fibroblast markers were reduced in PVL. ConclusionThese results demonstrate that PVL and conventional OLK are molecularly distinct with upregulation of many cancer-associated genes. They provide insight into the pathogenesis of PVL and show that biomarker based molecular diagnostics is feasible to discriminate and inform diagnosis and management.

Quantitative Analysis of Hair Luster in a Novel Ultraviolet-Irradiated Mouse Model.

Hair luster is a key attribute of healthy hair and a crucial aspect of cosmetic appeal, reflecting the overall health and vitality of hair. Despite its significance, the advancement of therapeutic strategies for hair luster enhancement have been limited due to the absence of an effective experimental model. This study aimed to establish a novel animal model to assess hair gloss, employing ultraviolet (UV) irradiation on C57BL/6 mice. Specifically, UVB irradiation was meticulously applied to the shaved skin of these mice, simulating conditions that typically lead to hair luster loss in humans. The regrowth and characteristics of the hair were evaluated using a dual approach: an Investigator's Global Assessment (IGA) scale for subjective assessment and an image-based pixel-count method for objective quantification. These methods provided a comprehensive understanding of the changes in hair quality post-irradiation. To explore the potential reversibility of hair luster changes, oral minoxidil was administered, a treatment known for its effects on hair growth and texture. Further, to gain insights into the underlying biological mechanisms, bulk RNA transcriptomic analysis of skin tissue was conducted. This analysis revealed significant alterations in the expression of keratin-associated protein (KRTAP) genes, suggesting modifications in hair keratin crosslinking due to UV exposure. These changes are crucial in understanding the molecular dynamics affecting hair luster. The development of this new mouse model is a significant advancement in hair care research. It not only facilitates the evaluation of hair luster in a controlled setting but also opens avenues for the research and development of innovative therapeutic strategies. This model holds promise for the formulation of more effective hair care products and treatments, potentially revolutionizing the approach towards managing and enhancing hair luster.

RNA Profile of Cell Bodies and Exosomes Released by Tumorigenic and Non-Tumorigenic Thyroid Cells.

Tumor cells release exosomes, extracellular vesicle containing various bioactive molecules such as protein, DNA and RNA. The analysis of RNA molecules packaged in exosomes may provide new potential diagnostic or prognostic tumor biomarkers. The treatment of radioiodine-refractory aggressive thyroid cancer is still an unresolved clinical challenge, and the search for biomarkers that are detectable in early phase of the disease has become a fundamental goal for thyroid cancer research. By using transcriptome analysis, this study aimed to analyze the gene expression profiles of exosomes secreted by a non-tumorigenic thyroid cell line (Nthy-ori 3.1-exo) and a papillary thyroid cancer (TPC-1-exo) cell line, comparing them with those of cell bodies (Nthy-ori 3.1-cells and TPC-1-cells). A total of 9107 transcripts were identified as differentially expressed when comparing TPC-1-exo with TPC-1-cells and 5861 when comparing Nthy-ori 3.1-exo with Nthy-ori 3.1-cells. Among them, Sialic acid-binding immunoglobulin-like lectins 10 and 11 (SIGLEC10, SIGLEC11) and Keratin-associated protein 5 (KRTAP5-3) transcripts, genes known to be involved in cancer progression, turned out to be up-regulated only in TPC-1-exo. Gene ontology analysis revealed significantly enriched pathways, and only in TPC-1-exo were the differential expressed genes associated with an up-regulation in epigenetic processes. These findings provide a proof of concept that some mRNA species are specifically packaged in tumor-cell-derived exosomes and may constitute a starting point for the identification of new biomarkers for thyroid tumors.

Downregulation of mRNAs Encoding Keratin-Associated Proteins in the Tongue of Mice Fed a High-Fat Diet

Downregulation of mRNAs Encoding Keratin-Associated Proteins in the Tongue of Mice Fed a High-Fat Diet

Key Factors in the Complex and Coordinated Network of Skin Keratinization: Their Significance and Involvement in Common Skin Conditions.

The epidermis serves many vital roles, including protecting the body from external influences and healing eventual injuries. It is maintained by an incredibly complex and perfectly coordinated keratinization process. In this process, desquamation is essential for the differentiation of epidermal basal progenitor cells into enucleated corneocytes, which subsequently desquamate through programmed death. Numerous factors control keratinocyte differentiation: epidermal growth factor, transforming growth factor-α, keratinocyte growth factor, interleukins IL-1-β and IL-6, elevated vitamin A levels, and changes in Ca2+ concentration. The backbone of the keratinocyte transformation process from mitotically active basal cells into fully differentiated, enucleated corneocytes is the expression of specific proteins and the creation of a Ca2+ and pH gradient at precise locations within the epidermis. Skin keratinization disorders (histologically characterized predominantly by dyskeratosis, parakeratosis, and hyperkeratosis) may be categorized into three groups: defects in the α-helical rod pattern, defects outside the α-helical rod domain, and disorders of keratin-associated proteins. Understanding the process of keratinization is essential for the pathogenesis of many dermatological diseases because improper desquamation and epidermopoiesis/keratinization (due to genetic mutations of factors or due to immune pathological processes) can lead to various conditions (ichthyoses, palmoplantar keratodermas, psoriasis, pityriasis rubra pilaris, epidermolytic hyperkeratosis, and others).

Ovine KRTAP36-2: A New Keratin-Associated Protein Gene Related to Variation in Wool Yield.

Keratin-associated proteins (KAPs) are structural components of wool fibres. High-glycine/tyrosine (HGT)-KAPs are a subset of the KAP family, and their abundance in fibres varies. In this study, we report the discovery of an ovine HGT-KAP gene to which we assigned the name KRTAP36-2. Polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP) analyses revealed four variants of this gene in a screening population of 170 sheep from a variety of breeds. The DNA sequencing of the variants revealed four single-nucleotide polymorphisms (SNPs) and a dinucleotide deletion. Three of these SNPs were in the coding region, and one of these was non-synonymous and potentially led to the amino acid substitution p.Cys27Gly near the middle of the protein. The remaining SNP was located near the putative TATA box, and the di-nucleotide deletion was near the putative transcription initiation site. The effect of this variation in KRTAP36-2 was investigated in 274 Southdown × Merino lambs that were the progeny of five sires. Variation was only found to be associated with wool yield, that is, the proportion of the greasy fleece that remained as clean fleece upon scouring (expressed as a percentage). This may have some value in increasing wool production.

158 The keratin-associated protein epiplakin is down-regulated in psoriasis

158 The keratin-associated protein epiplakin is down-regulated in psoriasis