| HGNC Family | Keratin associated proteins (KRTAP) |
| Name | keratin associated protein 4-2 |
| Description | This protein is a member of the keratin-associated protein (KAP) family. The KAP proteins form a matrix of keratin intermediate filaments which contribute to the structure of hair fibers. KAP family members appear to have unique, family-specific amino- and carboxyl-terminal regions and are subdivided into three multi-gene families according to amino acid composition: the high sulfur, the ultrahigh sulfur, and the high tyrosine/glycine KAPs. This protein is a member of the ultrahigh sulfur KAP family and the gene is localized to a cluster of KAPs at 17q12-q21. [provided by RefSeq, Jul 2008] |
| Summary |
{"type": "root", "children": [{"type": "p", "children": [{"type": "t", "text": "\n KRTAP4‐2 is a member of the keratin‐associated protein (KAP) family that plays an essential role in defining the physical and mechanical properties of hair and wool fibers. Data from studies in both rodents and sheep underline that proper expression of KAP family genes is crucial for normal hair follicle function and fiber structure. For instance, in mice, genetic mutations affecting hair follicle signaling pathways can result in alopecia and changes in the expression of structural genes, highlighting the importance of a tightly regulated network of genes—including those encoding KAPs—in maintaining hair integrity."}, {"type": "fg", "children": [{"type": "fg_fs", "start_ref": "1", "end_ref": "4"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n In sheep, experimental investigations have demonstrated that androgen levels can modulate the transcription of several KAP genes in wool follicles. Specifically, in cultured wool follicles from Hetian sheep, an optimal concentration of dihydrotestosterone was found to promote cell proliferation and upregulate the expression of multiple KAP genes, including KRTAP4‐2, suggesting that its expression is responsive to hormonal regulation and that it may contribute to improved fiber growth and strength."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "5"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Furthermore, studies in Merino sheep with the felting lustre (FL) mutation reveal that changes in the expression of KAP genes—including an upregulation of KRTAP4‐2—are associated with significant alterations in fiber structure, such as a reduction in specific cortical cell types. This shift in gene expression likely contributes to the unique characteristics of FL wool, including its felting properties and altered lustre."}, {"type": "fg", "children": [{"type": "fg_f", "ref": "6"}]}, {"type": "t", "text": "\n "}]}, {"type": "t", "text": "\n "}, {"type": "p", "children": [{"type": "t", "text": "\n Collectively, these findings indicate that KRTAP4‐2 functions as an important structural component in hair and wool fibers. Its regulated expression is critical for proper fiber development and quality, being sensitive to both genetic and hormonal cues that influence cell proliferation, differentiation, and the overall architecture of the hair shaft.\n "}]}, {"type": "rg", "children": [{"type": "r", "ref": 1, "children": [{"type": "t", "text": "Fabian Runkel, Maik Hintze, Sebastian Griesing, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Alopecia in a viable phospholipase C delta 1 and phospholipase C delta 3 double mutant."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2012)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0039203"}], "href": "https://doi.org/10.1371/journal.pone.0039203"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "22723964"}], "href": "https://pubmed.ncbi.nlm.nih.gov/22723964"}]}, {"type": "r", "ref": 2, "children": [{"type": "t", "text": "Fabrice Lopez, Julien Textoris, Aurélie Bergon, et al. "}, {"type": "b", "children": [{"type": "t", "text": "TranscriptomeBrowser: a powerful and flexible toolbox to explore productively the transcriptional landscape of the Gene Expression Omnibus database."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "PLoS One (2008)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1371/journal.pone.0004001"}], "href": "https://doi.org/10.1371/journal.pone.0004001"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "19104654"}], "href": "https://pubmed.ncbi.nlm.nih.gov/19104654"}]}, {"type": "r", "ref": 3, "children": [{"type": "t", "text": "Karsten Boldt, Jeroen van Reeuwijk, Qianhao Lu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "An organelle-specific protein landscape identifies novel diseases and molecular mechanisms."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Nat Commun (2016)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1038/ncomms11491"}], "href": "https://doi.org/10.1038/ncomms11491"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "27173435"}], "href": "https://pubmed.ncbi.nlm.nih.gov/27173435"}]}, {"type": "r", "ref": 4, "children": [{"type": "t", "text": "Renato Polimanti, Huiping Zhang, Andrew H Smith, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Genome-wide association study of body mass index in subjects with alcohol dependence."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Addict Biol (2017)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/adb.12317"}], "href": "https://doi.org/10.1111/adb.12317"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "26458734"}], "href": "https://pubmed.ncbi.nlm.nih.gov/26458734"}]}, {"type": "r", "ref": 5, "children": [{"type": "t", "text": "H Y Wang, S W Li, T H Wu, et al. "}, {"type": "b", "children": [{"type": "t", "text": "The effect of androgen on wool follicles and keratin production in Hetian sheep."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Braz J Biol (2021)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1590/1519-6984.224056"}], "href": "https://doi.org/10.1590/1519-6984.224056"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "33470295"}], "href": "https://pubmed.ncbi.nlm.nih.gov/33470295"}]}, {"type": "r", "ref": 6, "children": [{"type": "t", "text": "Shu Wei Li, Hong Sheng Ouyang, George Ernest Rogers, et al. "}, {"type": "b", "children": [{"type": "t", "text": "Characterization of the structural and molecular defects in fibres and follicles of the Merino felting lustre mutant."}]}, {"type": "t", "text": " "}, {"type": "i", "children": [{"type": "t", "text": "Exp Dermatol (2009)"}]}, {"type": "t", "text": " DOI: "}, {"type": "a", "children": [{"type": "t", "text": "10.1111/j.1600-0625.2008.00774.x"}], "href": "https://doi.org/10.1111/j.1600-0625.2008.00774.x"}, {"type": "t", "text": " PMID: "}, {"type": "a", "children": [{"type": "t", "text": "18637126"}], "href": "https://pubmed.ncbi.nlm.nih.gov/18637126"}]}]}]}
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| Synonyms | KAP4.2, KRTAP4.2 |
| Proteins | KRA42_HUMAN |
| NCBI Gene ID | 85291 |
| API | |
| Download Associations | |
| Predicted Functions |
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| Co-expressed Genes |
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| Expression in Tissues and Cell Lines |
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KRTAP4-2 has 980 functional associations with biological entities spanning 8 categories (molecular profile, organism, functional term, phrase or reference, disease, phenotype or trait, chemical, structural feature, cell line, cell type or tissue, gene, protein or microRNA) extracted from 48 datasets.
Click the + buttons to view associations for KRTAP4-2 from the datasets below.
If available, associations are ranked by standardized value
| Dataset | Summary | |
|---|---|---|
| Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles | tissues with high or low expression of KRTAP4-2 gene relative to other tissues from the Allen Brain Atlas Adult Human Brain Tissue Gene Expression Profiles dataset. | |
| Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles | tissue samples with high or low expression of KRTAP4-2 gene relative to other tissue samples from the Allen Brain Atlas Aging Dementia and Traumatic Brain Injury Tissue Sample Gene Expression Profiles dataset. | |
| Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray | tissue samples with high or low expression of KRTAP4-2 gene relative to other tissue samples from the Allen Brain Atlas Developing Human Brain Tissue Gene Expression Profiles by Microarray dataset. | |
| Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles | tissues with high or low expression of KRTAP4-2 gene relative to other tissues from the Allen Brain Atlas Prenatal Human Brain Tissue Gene Expression Profiles dataset. | |
| BioGPS Human Cell Type and Tissue Gene Expression Profiles | cell types and tissues with high or low expression of KRTAP4-2 gene relative to other cell types and tissues from the BioGPS Human Cell Type and Tissue Gene Expression Profiles dataset. | |
| CCLE Cell Line Gene CNV Profiles | cell lines with high or low copy number of KRTAP4-2 gene relative to other cell lines from the CCLE Cell Line Gene CNV Profiles dataset. | |
| CCLE Cell Line Gene Expression Profiles | cell lines with high or low expression of KRTAP4-2 gene relative to other cell lines from the CCLE Cell Line Gene Expression Profiles dataset. | |
| ChEA Transcription Factor Binding Site Profiles | transcription factor binding site profiles with transcription factor binding evidence at the promoter of KRTAP4-2 gene from the CHEA Transcription Factor Binding Site Profiles dataset. | |
| ChEA Transcription Factor Targets | transcription factors binding the promoter of KRTAP4-2 gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets dataset. | |
| ChEA Transcription Factor Targets 2022 | transcription factors binding the promoter of KRTAP4-2 gene in low- or high-throughput transcription factor functional studies from the CHEA Transcription Factor Targets 2022 dataset. | |
| COMPARTMENTS Curated Protein Localization Evidence Scores | cellular components containing KRTAP4-2 protein from the COMPARTMENTS Curated Protein Localization Evidence Scores dataset. | |
| COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 | cellular components co-occuring with KRTAP4-2 protein in abstracts of biomedical publications from the COMPARTMENTS Text-mining Protein Localization Evidence Scores 2025 dataset. | |
| COSMIC Cell Line Gene CNV Profiles | cell lines with high or low copy number of KRTAP4-2 gene relative to other cell lines from the COSMIC Cell Line Gene CNV Profiles dataset. | |
| COSMIC Cell Line Gene Mutation Profiles | cell lines with KRTAP4-2 gene mutations from the COSMIC Cell Line Gene Mutation Profiles dataset. | |
| DISEASES Text-mining Gene-Disease Association Evidence Scores 2025 | diseases co-occuring with KRTAP4-2 gene in abstracts of biomedical publications from the DISEASES Text-mining Gene-Disease Assocation Evidence Scores 2025 dataset. | |
| ENCODE Histone Modification Site Profiles | histone modification site profiles with high histone modification abundance at KRTAP4-2 gene from the ENCODE Histone Modification Site Profiles dataset. | |
| ENCODE Transcription Factor Binding Site Profiles | transcription factor binding site profiles with transcription factor binding evidence at the promoter of KRTAP4-2 gene from the ENCODE Transcription Factor Binding Site Profiles dataset. | |
| ENCODE Transcription Factor Targets | transcription factors binding the promoter of KRTAP4-2 gene in ChIP-seq datasets from the ENCODE Transcription Factor Targets dataset. | |
| GeneSigDB Published Gene Signatures | PubMedIDs of publications reporting gene signatures containing KRTAP4-2 from the GeneSigDB Published Gene Signatures dataset. | |
| GEO Signatures of Differentially Expressed Genes for Diseases | disease perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Diseases dataset. | |
| GEO Signatures of Differentially Expressed Genes for Gene Perturbations | gene perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Gene Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Kinase Perturbations | kinase perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Kinase Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Small Molecules | small molecule perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Small Molecules dataset. | |
| GEO Signatures of Differentially Expressed Genes for Transcription Factor Perturbations | transcription factor perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Transcription Factor Perturbations dataset. | |
| GEO Signatures of Differentially Expressed Genes for Viral Infections | virus perturbations changing expression of KRTAP4-2 gene from the GEO Signatures of Differentially Expressed Genes for Viral Infections dataset. | |
| GO Cellular Component Annotations 2015 | cellular components containing KRTAP4-2 protein from the curated GO Cellular Component Annotations 2015 dataset. | |
| GO Molecular Function Annotations 2015 | molecular functions performed by KRTAP4-2 gene from the curated GO Molecular Function Annotations 2015 dataset. | |
| GTEx Tissue Gene Expression Profiles | tissues with high or low expression of KRTAP4-2 gene relative to other tissues from the GTEx Tissue Gene Expression Profiles dataset. | |
| GTEx Tissue Gene Expression Profiles 2023 | tissues with high or low expression of KRTAP4-2 gene relative to other tissues from the GTEx Tissue Gene Expression Profiles 2023 dataset. | |
| Heiser et al., PNAS, 2011 Cell Line Gene Expression Profiles | cell lines with high or low expression of KRTAP4-2 gene relative to other cell lines from the Heiser et al., PNAS, 2011 Cell Line Gene Expression Profiles dataset. | |
| InterPro Predicted Protein Domain Annotations | protein domains predicted for KRTAP4-2 protein from the InterPro Predicted Protein Domain Annotations dataset. | |
| JASPAR Predicted Human Transcription Factor Targets 2025 | transcription factors regulating expression of KRTAP4-2 gene predicted using known transcription factor binding site motifs from the JASPAR Predicted Human Transcription Factor Targets dataset. | |
| JASPAR Predicted Transcription Factor Targets | transcription factors regulating expression of KRTAP4-2 gene predicted using known transcription factor binding site motifs from the JASPAR Predicted Transcription Factor Targets dataset. | |
| Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene CNV Profiles | cell lines with high or low copy number of KRTAP4-2 gene relative to other cell lines from the Klijn et al., Nat. Biotechnol., 2015 Cell Line Gene CNV Profiles dataset. | |
| KnockTF Gene Expression Profiles with Transcription Factor Perturbations | transcription factor perturbations changing expression of KRTAP4-2 gene from the KnockTF Gene Expression Profiles with Transcription Factor Perturbations dataset. | |
| LOCATE Predicted Protein Localization Annotations | cellular components predicted to contain KRTAP4-2 protein from the LOCATE Predicted Protein Localization Annotations dataset. | |
| MiRTarBase microRNA Targets | microRNAs targeting KRTAP4-2 gene in low- or high-throughput microRNA targeting studies from the MiRTarBase microRNA Targets dataset. | |
| MotifMap Predicted Transcription Factor Targets | transcription factors regulating expression of KRTAP4-2 gene predicted using known transcription factor binding site motifs from the MotifMap Predicted Transcription Factor Targets dataset. | |
| PerturbAtlas Signatures of Differentially Expressed Genes for Gene Perturbations | gene perturbations changing expression of KRTAP4-2 gene from the PerturbAtlas Signatures of Differentially Expressed Genes for Gene Perturbations dataset. | |
| Reactome Pathways 2024 | pathways involving KRTAP4-2 protein from the Reactome Pathways 2024 dataset. | |
| Roadmap Epigenomics Histone Modification Site Profiles | histone modification site profiles with high histone modification abundance at KRTAP4-2 gene from the Roadmap Epigenomics Histone Modification Site Profiles dataset. | |
| RummaGEO Drug Perturbation Signatures | drug perturbations changing expression of KRTAP4-2 gene from the RummaGEO Drug Perturbation Signatures dataset. | |
| RummaGEO Gene Perturbation Signatures | gene perturbations changing expression of KRTAP4-2 gene from the RummaGEO Gene Perturbation Signatures dataset. | |
| TargetScan Predicted Nonconserved microRNA Targets | microRNAs regulating expression of KRTAP4-2 gene predicted using nonconserved miRNA seed sequences from the TargetScan Predicted Nonconserved microRNA Targets dataset. | |
| TCGA Signatures of Differentially Expressed Genes for Tumors | tissue samples with high or low expression of KRTAP4-2 gene relative to other tissue samples from the TCGA Signatures of Differentially Expressed Genes for Tumors dataset. | |
| TISSUES Curated Tissue Protein Expression Evidence Scores | tissues with high expression of KRTAP4-2 protein from the TISSUES Curated Tissue Protein Expression Evidence Scores dataset. | |
| TISSUES Curated Tissue Protein Expression Evidence Scores 2025 | tissues with high expression of KRTAP4-2 protein from the TISSUES Curated Tissue Protein Expression Evidence Scores 2025 dataset. | |
| TISSUES Text-mining Tissue Protein Expression Evidence Scores 2025 | tissues co-occuring with KRTAP4-2 protein in abstracts of biomedical publications from the TISSUES Text-mining Tissue Protein Expression Evidence Scores 2025 dataset. | |
