KRTAP4-1

gene

On this page

Also known as KAP4.1KAP4.10

Summary

KRTAP4-1 (keratin associated protein 4-1, HGNC:18907) is a protein-coding gene on chromosome 17q21.2, encoding Keratin-associated protein 4-1 (Q9BYQ7). In the hair cortex, hair keratin intermediate filaments are embedded in an interfilamentous matrix, consisting of hair keratin-associated proteins (KRTAP), which are essential for the formation of a rigid and resistant hair shaft through their extensive disulfide bond cross-link….

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.

Source: NCBI Gene 85285 — RefSeq curated summary.

At a glance

Clinical variants (ClinVar): 35 total
MANE Select transcript: NM_001386841

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:18907
Approved symbol	KRTAP4-1
Name	keratin associated protein 4-1
Location	17q21.2
Locus type	gene with protein product
Status	Approved
Aliases	KAP4.1, KAP4.10
Ensembl gene	ENSG00000198443
Ensembl biotype	protein_coding
Entrez	85285

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000398472

RefSeq mRNA: 1 — MANE Select: NM_001386841 NM_001386841

CCDS: CCDS92305

Canonical transcript exons

ENST00000398472 — 1 exons

Exon	Start	End
ENSE00001533286	41184100	41184911

Expression profiles

Bgee: expression breadth broad, 37 present calls, max score 75.70.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 0.0324 / max 37.8736, expressed in 4 samples.

FANTOM5 promoters (1 alternative TSS)

Promoter ID	TPM avg	Samples expressed
165881	0.0324	4

Top tissues by expression

208 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
upper arm skin	UBERON:0004263	75.70	silver quality
ileal mucosa	UBERON:0000331	63.97	silver quality
mucosa of transverse colon	UBERON:0004991	61.02	gold quality
cardiac muscle of right atrium	UBERON:0003379	54.34	gold quality
left ventricle myocardium	UBERON:0006566	54.23	gold quality
kidney epithelium	UBERON:0004819	53.93	gold quality
epithelial cell of pancreas	CL:0000083	53.90	gold quality
pancreatic ductal cell	CL:0002079	53.86	silver quality
tibialis anterior	UBERON:0001385	53.44	silver quality
deltoid	UBERON:0001476	50.66	gold quality
myocardium	UBERON:0002349	50.25	gold quality
upper leg skin	UBERON:0004262	49.20	silver quality
quadriceps femoris	UBERON:0001377	47.23	gold quality
nasal cavity epithelium	UBERON:0005384	47.03	gold quality
vastus lateralis	UBERON:0001379	45.40	gold quality
transverse colon	UBERON:0001157	45.03	gold quality
placenta	UBERON:0001987	44.09	gold quality
skin of hip	UBERON:0001554	43.75	silver quality
layer of synovial tissue	UBERON:0007616	43.55	gold quality
skeletal muscle tissue of rectus abdominis	UBERON:0004511	43.37	gold quality
buccal mucosa cell	CL:0002336	43.16	gold quality
secondary oocyte	CL:0000655	42.57	gold quality
penis	UBERON:0000989	42.53	gold quality
zone of skin	UBERON:0000014	41.82	gold quality
muscle tissue	UBERON:0002385	41.41	gold quality
skeletal muscle tissue	UBERON:0001134	41.34	gold quality
superficial temporal artery	UBERON:0001614	41.33	gold quality
palpebral conjunctiva	UBERON:0001812	41.10	gold quality
mucosa of paranasal sinus	UBERON:0005030	40.98	gold quality
skin of abdomen	UBERON:0001416	40.96	gold quality

Single-cell (SCXA)

Detected in 1 experiment(s), a significant marker in 0.

Experiment	Marker?	Max mean expression
E-ANND-3	no	1.47

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

35 targeting KRTAP4-1, top 30 by miRDB confidence (max_score; target_count = how many genes the miRNA targets in total — lower means more specific):

miRNA	Max score	Avg score	miRNA target_count
HSA-MIR-4481	100.00	66.42	1669
HSA-MIR-5692B	100.00	71.32	2622
HSA-MIR-5692C	100.00	71.32	2622
HSA-MIR-3185	99.99	68.12	1959
HSA-MIR-4745-5P	99.98	65.95	1028
HSA-MIR-302C-5P	99.97	72.56	3642
HSA-MIR-380-3P	99.89	70.18	1978
HSA-MIR-7162-3P	99.89	68.16	1682
HSA-MIR-6739-5P	99.80	67.87	2806
HSA-MIR-4668-5P	99.79	70.58	3782
HSA-MIR-320A-3P	99.77	69.73	2107
HSA-MIR-320B	99.77	69.73	2107
HSA-MIR-320C	99.77	69.73	2107
HSA-MIR-320D	99.77	69.73	2107
HSA-MIR-4429	99.77	69.62	2111
HSA-MIR-6733-5P	99.74	67.94	2759
HSA-MIR-132-3P	99.73	70.56	1424
HSA-MIR-212-3P	99.73	70.65	1424
HSA-MIR-6505-5P	99.73	69.25	1595
HSA-MIR-425-5P	99.59	67.67	900
HSA-MIR-1252-3P	99.55	67.71	2862
HSA-MIR-3153	99.55	67.59	2337
HSA-MIR-10522-5P	99.26	68.50	2087
HSA-MIR-149-5P	99.25	67.16	1315
HSA-MIR-4717-3P	99.06	66.34	1072
HSA-MIR-4709-3P	98.88	68.04	1594
HSA-MIR-3145-3P	98.85	69.07	2031
HSA-MIR-4477A	98.83	69.75	2952
HSA-MIR-4773	98.35	67.30	1710
HSA-MIR-2681-3P	98.18	65.28	577

Cross-species orthologs

8 orthologs

Organism	Symbol	Gene ID
mus_musculus	Krtap4-16	ENSMUSG00000046474
mus_musculus	Krtap5-2	ENSMUSG00000054759
mus_musculus	Krtap5-20	ENSMUSG00000056885
mus_musculus	Krtap5-26	ENSMUSG00000109859
mus_musculus	Krtap5-24	ENSMUSG00000110324
rattus_norvegicus	Krtap5-8	ENSRNOG00000020131
rattus_norvegicus	Krtap4-3	ENSRNOG00000034110
rattus_norvegicus	AABR07006049.1	ENSRNOG00000046649

Paralogs (47): KRTAP4-4 (ENSG00000171396), KRTAP9-7 (ENSG00000180386), KRTAP5-5 (ENSG00000185940), KRTAP12-1 (ENSG00000187175), KRTAP9-8 (ENSG00000187272), KRTAP10-8 (ENSG00000187766), KRTAP10-6 (ENSG00000188155), KRTAP1-1 (ENSG00000188581), KRTAP10-12 (ENSG00000189169), KRTAP4-3 (ENSG00000196156), KRTAP9-9 (ENSG00000198083), KRTAP4-6 (ENSG00000198090), KRTAP4-5 (ENSG00000198271), KRTAP9-3 (ENSG00000204873), KRTAP4-8 (ENSG00000204880), KRTAP1-4 (ENSG00000204887), KRTAP12-3 (ENSG00000205439), KRTAP10-2 (ENSG00000205445), KRTAP5-6 (ENSG00000205864), KRTAP5-2 (ENSG00000205867), KRTAP16-1 (ENSG00000212657), KRTAP9-6 (ENSG00000212659), KRTAP4-11 (ENSG00000212721), KRTAP4-9 (ENSG00000212722), KRTAP2-3 (ENSG00000212724), KRTAP2-1 (ENSG00000212725), KRTAP10-3 (ENSG00000212935), KRTAP4-12 (ENSG00000213416), KRTAP2-4 (ENSG00000213417), KRTAP2-2 (ENSG00000214518), KRTAP10-4 (ENSG00000215454), KRTAP10-1 (ENSG00000215455), KRTAP10-9 (ENSG00000221837), KRTAP1-5 (ENSG00000221852), KRTAP10-10 (ENSG00000221859), KRTAP12-2 (ENSG00000221864), KRTAP1-3 (ENSG00000221880), KRTAP9-2 (ENSG00000239886), KRTAP9-1 (ENSG00000240542), KRTAP4-7 (ENSG00000240871)

Protein

Protein identifiers

Keratin-associated protein 4-1 — Q9BYQ7 (reviewed: Q9BYQ7)

Alternative names: Keratin-associated protein 4-10, Keratin-associated protein 4.1, Keratin-associated protein 4.10, Ultrahigh sulfur keratin-associated protein 4.10

All UniProt accessions (1): Q9BYQ7

UniProt curated annotations — full annotation on UniProt →

Function. In the hair cortex, hair keratin intermediate filaments are embedded in an interfilamentous matrix, consisting of hair keratin-associated proteins (KRTAP), which are essential for the formation of a rigid and resistant hair shaft through their extensive disulfide bond cross-linking with abundant cysteine residues of hair keratins. The matrix proteins include the high-sulfur and high-glycine-tyrosine keratins.

Subunit / interactions. Interacts with hair keratins.

Tissue specificity. Expressed in the hair follicles.

Polymorphism. Numerous size polymorphism are present in KRTAP4 gene family, which are mainly due to variations in the sequence encoding cysteine-rich repeat segments.

Similarity. Belongs to the KRTAP type 4 family.

RefSeq proteins (1): NP_001373770* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR002494	KAP	Family

Pfam: PF13885

UniProt features (24 total): repeat 18, sequence variant 4, chain 1, region of interest 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q9BYQ7-F1	36.87	0.00

Function

Pathways and Gene Ontology

Reactome pathways

2 pathways

ID	Pathway
R-HSA-6805567	Keratinization
R-HSA-1266738	Developmental Biology

MSigDB gene sets: 39 (showing top): MARTINEZ_RB1_TARGETS_DN, TGGAAA_NFAT_Q4_01, GOCC_INTERMEDIATE_FILAMENT_CYTOSKELETON, GOCC_KERATIN_FILAMENT, GOCC_SUPRAMOLECULAR_COMPLEX, GOCC_POLYMERIC_CYTOSKELETAL_FIBER, REACTOME_KERATINIZATION, NFE2L2.V2, GOCC_SUPRAMOLECULAR_POLYMER, HMGA1_TARGET_GENES, ZNF768_TARGET_GENES, MIR4668_5P, MIR380_3P, MIR212_3P, MIR132_3P

GO Biological Process (0):

GO Molecular Function (1): protein binding (GO:0005515)

GO Cellular Component (3): cytosol (GO:0005829), keratin filament (GO:0045095), intermediate filament (GO:0005882)

Reactome top-level categories

Rollup of top-1 pathways:

Category	Pathways
Developmental Biology	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
binding	1
cytoplasm	1
cellular anatomical structure	1
intermediate filament	1
intermediate filament cytoskeleton	1
polymeric cytoskeletal fiber	1

Protein interactions and networks

STRING

200 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
KRTAP4-1	KRTAP5-11	Q6L8G4	574
KRTAP4-1	A8MUN0	A8MUN0	572
KRTAP4-1	KRTAP3-3	Q9BYR6	571
KRTAP4-1	KRTAP3-1	Q9BYR8	519
KRTAP4-1	KRTAP22-1	Q3MIV0	517
KRTAP4-1	KRTAP3-2	Q9BYR7	507
KRTAP4-1	KRTAP1-4	P0C5Y4	506
KRTAP4-1	KRTAP13-3	Q3SY46	494
KRTAP4-1	KRTAP6-3	Q3LI67	480
KRTAP4-1	KRTAP6-2	Q3LI66	479
KRTAP4-1	KRTAP24-1	Q3LI83	476
KRTAP4-1	KRTAP26-1	Q6PEX3	475
KRTAP4-1	KRTAP17-1	Q9BYP8	453
KRTAP4-1	KRTAP6-1	Q3LI64	447
KRTAP4-1	KRTAP2-3	P0C7H8	447

IntAct

79 interactions, top by confidence:

A	B	Type	Score
KRTAP4-1	LCE2D	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	GNE	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	CRCT1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE1D	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	KRTAP5-6	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	CATSPER1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	VASN	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	IL10	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE1B	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	NPDC1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	OTX1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE3A	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	KRTAP9-3	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	PSMA1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	KRTAP9-8	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE3E	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE5A	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	HOXA1	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	SMCP	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE3C	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	FBXW5	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	NECTIN3	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	LCE3D	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	NUFIP2	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	CREB5	psi-mi:“MI:0915”(physical association)	0.560
KRTAP4-1	DHRS1	psi-mi:“MI:0915”(physical association)	0.560
LCE2D	KRTAP4-1	psi-mi:“MI:0915”(physical association)	0.000
GNE	KRTAP4-1	psi-mi:“MI:0915”(physical association)	0.000
CRCT1	KRTAP4-1	psi-mi:“MI:0915”(physical association)	0.000
LCE1D	KRTAP4-1	psi-mi:“MI:0915”(physical association)	0.000

BioGRID (30): KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid), KRTAP4-1 (Two-hybrid)

ESM2 similar proteins: A0A286YEV6, A0A286YEX9, A0A286YEY9, A0A286YF01, A0A286YF46, A0A286YF60, A0A286YF77, A0A286YFB4, A0A286YFG1, O14633, P02438, P04459, P05687, P05688, P08131, P08175, P0DSO2, P20730, Q01642, Q01643, Q01644, Q01645, Q07627, Q3LI58, Q3LI59, Q3V2C1, Q5T750, Q5T752, Q5T754, Q5TA78, Q5TA79, Q5TA81, Q5TA82, Q5TCM9, Q8IUC1, Q8IUG1, Q9BQ66, Q9BYP8, Q9BYQ5, Q9BYQ6

SIGNOR signaling

0 interactions.

Enriched among interaction partners

Reactome pathways and GO biological processes over-represented among this gene’s 26 IntAct physical interaction partners (hypergeometric vs the genome-wide background, BH-FDR, gene-set size 15–500, ranked by fold). A functional readout of the neighbourhood — distinct from this gene’s own memberships above, and biased toward well-studied / hub proteins, so read it as themes rather than proof.

Reactome pathways:

Pathway	Partners	Fold	FDR
Formation of the cornified envelope	8	37.0×	7e-10
Keratinization	11	32.2×	3e-13

GO biological processes:

GO term	Partners	Fold	FDR
keratinization	8	98.5×	7e-13

Disease & clinical

Clinical variants and AI predictions

ClinVar

35 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	33
Likely benign	1
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

56 predictions. Top by Δscore:

Variant	Effect	Δscore
17:41184811:CAGCC:C	acceptor_gain	0.8500
17:41184836:C:CT	acceptor_gain	0.7200
17:41184815:CCTGG:C	acceptor_loss	0.7100
17:41184816:C:CA	acceptor_loss	0.7100
17:41184816:C:CC	acceptor_gain	0.6600
17:41184814:CC:C	acceptor_gain	0.6400
17:41184815:CC:C	acceptor_gain	0.6400
17:41184821:C:CT	acceptor_gain	0.6400
17:41184826:C:CT	acceptor_gain	0.6300
17:41184813:GCC:G	acceptor_gain	0.6000
17:41184814:CCC:C	acceptor_gain	0.6000
17:41184836:C:T	acceptor_gain	0.6000
17:41184818:G:C	acceptor_loss	0.5200
17:41184835:C:CT	acceptor_loss	0.4600
17:41184822:A:T	acceptor_gain	0.4400
17:41184812:AGCC:A	acceptor_gain	0.4300
17:41184819:G:GC	acceptor_loss	0.4300
17:41184816:C:T	acceptor_gain	0.4000
17:41184827:A:T	acceptor_gain	0.4000
17:41184829:A:C	acceptor_loss	0.4000
17:41184848:TAA:T	acceptor_loss	0.3900
17:41184847:T:TC	acceptor_loss	0.3700
17:41184531:AC:A	acceptor_gain	0.3600
17:41184828:G:GT	acceptor_loss	0.3600
17:41184830:C:CT	acceptor_gain	0.3500
17:41184837:A:T	acceptor_loss	0.3500
17:41184823:G:GC	acceptor_loss	0.3400
17:41184813:GCCCT:G	acceptor_gain	0.3300
17:41184820:T:TC	acceptor_loss	0.3300
17:41184846:GTTAA:G	acceptor_loss	0.3300

AlphaMissense

964 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
17:41184609:G:C	S82R	0.620
17:41184609:G:T	S82R	0.620
17:41184611:T:G	S82R	0.620
17:41184495:G:C	S120R	0.607
17:41184495:G:T	S120R	0.607
17:41184497:T:G	S120R	0.607

dbSNP variants (sampled 300 via entrez): RS1002311362 (17:41183629 C>T), RS1003699755 (17:41184930 T>C), RS1004799308 (17:41184276 T>C), RS1005390111 (17:41185906 G>C), RS1007409 (17:41184759 G>A,C), RS1008928491 (17:41184187 G>A), RS1011345882 (17:41183644 A>T), RS1011561341 (17:41185398 A>G), RS1012173958 (17:41186608 A>G), RS1012883341 (17:41186744 C>G), RS1013370826 (17:41186499 G>T), RS1015808030 (17:41184282 T>G), RS1016327185 (17:41185735 C>G), RS1016779253 (17:41186252 G>A), RS1017222310 (17:41185952 A>G)

Disease associations

OMIM: gene `` | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

0 total (0 of 0 shown, HPO-id order):

GWAS associations

0 associations (top):

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

PharmGKB: 1 entry (VIP=true, CPIC=false)

CTD chemical–gene interactions

9 total (human), top 9 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
propionaldehyde	decreases expression	1
butyraldehyde	decreases expression	1
pentanal	decreases expression	1
Resveratrol	decreases expression, affects cotreatment	1
Aldehydes	decreases expression	1
Benzo(a)pyrene	increases methylation	1
Plant Extracts	affects cotreatment, decreases expression	1
Silicon Dioxide	decreases expression	1
Aflatoxin B1	decreases methylation	1

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.

No linked Atlas pages yet — the cross-entity mesh grows as the corpus expands.