KRTAP26-1

Summary

KRTAP26-1 (keratin associated protein 26-1, HGNC:33760) is a protein-coding gene on chromosome 21q22.11, encoding Keratin-associated protein 26-1 (Q6PEX3). 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….

Predicted to enable structural molecule activity. Predicted to be located in cytosol.

Source: NCBI Gene 388818 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 32 total
• MANE Select transcript: NM_203405

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:33760
Approved symbol	KRTAP26-1
Name	keratin associated protein 26-1
Location	21q22.11
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000197683
Ensembl biotype	protein_coding
Entrez	388818

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000360542

RefSeq mRNA: 1 — MANE Select: NM_203405 NM_203405

CCDS: CCDS13588

Canonical transcript exons

ENST00000360542 — 1 exons

Exon	Start	End
ENSE00001402413	30319124	30320315

Expression profiles

Bgee: expression breadth broad, 13 present calls, max score 81.35.

FANTOM5 (CAGE): breadth tissue_specific, TPM avg 0.0958 / max 84.3897, expressed in 7 samples.

FANTOM5 promoters (4 alternative TSS)

Promoter ID	TPM avg	Samples expressed
190119	0.0653	7
190122	0.0138	3
190121	0.0088	1
190120	0.0079	1

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
male germ line stem cell (sensu Vertebrata) in testis	CL:0000089 ∩ UBERON:0000473	81.35	silver quality
thymus	UBERON:0002370	61.87	gold quality
vastus lateralis	UBERON:0001379	60.14	gold quality
quadriceps femoris	UBERON:0001377	60.02	gold quality
placenta	UBERON:0001987	59.91	gold quality
trachea	UBERON:0003126	59.07	gold quality
dorsal plus ventral thalamus	UBERON:0001897	59.03	gold quality
dorsal root ganglion	UBERON:0000044	58.67	gold quality
epithelium of bronchus	UBERON:0002031	58.19	gold quality
layer of synovial tissue	UBERON:0007616	57.91	gold quality
cerebellar vermis	UBERON:0004720	57.59	gold quality
metanephric glomerulus	UBERON:0004736	55.97	gold quality
frontal pole	UBERON:0002795	50.41	gold quality
middle frontal gyrus	UBERON:0002702	50.30	gold quality
paraflocculus	UBERON:0005351	50.18	gold quality
Brodmann (1909) area 10	UBERON:0013541	50.18	gold quality
endometrium epithelium	UBERON:0004811	46.85	gold quality
lower esophagus mucosa	UBERON:0035834	38.72	gold quality
colonic epithelium	UBERON:0000397	37.20	gold quality
ventricular zone	UBERON:0003053	36.48	gold quality
cortical plate	UBERON:0005343	36.47	gold quality
bone marrow cell	CL:0002092	36.16	gold quality
sural nerve	UBERON:0015488	35.99	gold quality
skin of abdomen	UBERON:0001416	35.96	gold quality
ganglionic eminence	UBERON:0004023	35.49	gold quality
zone of skin	UBERON:0000014	35.13	gold quality
skin of leg	UBERON:0001511	34.60	gold quality
skeletal muscle tissue	UBERON:0001134	34.14	gold quality
bone marrow	UBERON:0002371	33.58	gold quality
muscle tissue	UBERON:0002385	33.03	gold quality

Single-cell (SCXA)

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

Experiment	Marker?	Max mean expression
E-ANND-3	no	1.80

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

32 targeting KRTAP26-1, 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-19A-3P	99.98	75.33	2762
HSA-MIR-19B-3P	99.98	75.44	2754
HSA-MIR-548P	99.98	72.25	3784
HSA-MIR-570-3P	99.96	72.41	4910
HSA-MIR-454-3P	99.91	74.01	1925
HSA-MIR-130A-3P	99.90	73.31	1861
HSA-MIR-130B-3P	99.90	73.27	1850
HSA-MIR-301A-3P	99.90	73.15	1839
HSA-MIR-301B-3P	99.90	73.19	1836
HSA-MIR-3666	99.90	73.24	1833
HSA-MIR-4295	99.90	73.11	1838
HSA-MIR-4671-3P	99.88	72.46	1045
HSA-MIR-577	99.78	69.13	2479
HSA-MIR-548AJ-5P	99.78	71.12	3085
HSA-MIR-548F-5P	99.78	71.02	3093
HSA-MIR-548G-5P	99.78	71.12	3085
HSA-MIR-548X-5P	99.78	71.12	3085
HSA-MIR-3934-3P	99.76	65.51	1351
HSA-MIR-4729	99.69	72.18	4233
HSA-MIR-545-5P	99.66	70.18	2308
HSA-MIR-6715B-5P	99.64	69.63	1420
HSA-MIR-4269	99.55	69.89	1373
HSA-MIR-6507-3P	99.35	67.32	1059
HSA-MIR-6830-5P	99.01	68.73	1884
HSA-MIR-3691-5P	98.62	65.88	552
HSA-MIR-653-3P	98.31	67.71	1542
HSA-MIR-5585-3P	98.25	67.41	941
HSA-MIR-561-5P	98.25	68.13	1365
HSA-MIR-5089-3P	97.50	67.82	758
HSA-MIR-759	96.16	66.77	873

Cross-species orthologs

2 orthologs

Organism	Symbol	Gene ID
mus_musculus	Krtap26-1	ENSMUSG00000071471
rattus_norvegicus	Krtap26-1	ENSRNOG00000048212

Paralogs (8): KRTAP11-1 (ENSG00000182591), KRTAP13-2 (ENSG00000182816), KRTAP15-1 (ENSG00000186970), KRTAP13-4 (ENSG00000186971), KRTAP13-1 (ENSG00000198390), KRTAP27-1 (ENSG00000206107), KRTAP25-1 (ENSG00000232263), KRTAP13-3 (ENSG00000240432)

Protein

Protein identifiers

Keratin-associated protein 26-1 — Q6PEX3 (reviewed: Q6PEX3)

All UniProt accessions (1): Q6PEX3

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. Localized high up in the well differentiated portion of the hair follicle cuticle (about 10-15 cell layers above the apex of the dermal papilla).

Similarity. Belongs to the PMG family.

RefSeq proteins (1): NP_981950* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR007659	Keratin_matx	Family
IPR007951	KRTAP_PMG	Family

Pfam: PF05287

UniProt features (3 total): sequence variant 2, chain 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q6PEX3-F1	42.53	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: 53 (showing top): FREDERICK_PRKCI_TARGETS, chr21q22, GOCC_INTERMEDIATE_FILAMENT_CYTOSKELETON, GOCC_KERATIN_FILAMENT, GOMF_STRUCTURAL_MOLECULE_ACTIVITY, GOCC_SUPRAMOLECULAR_COMPLEX, GOCC_POLYMERIC_CYTOSKELETAL_FIBER, REACTOME_KERATINIZATION, GOCC_SUPRAMOLECULAR_POLYMER, MIR570_3P, MIR454_3P, MIR130A_3P, MIR130B_3P, MIR4295, MIR301A_3P

GO Biological Process (0):

GO Molecular Function (2): structural molecule activity (GO:0005198), 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
molecular_function	1
binding	1
cytoplasm	1
cellular anatomical structure	1
intermediate filament	1
intermediate filament cytoskeleton	1
polymeric cytoskeletal fiber	1

Protein interactions and networks

STRING

384 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
KRTAP26-1	KRTAP22-1	Q3MIV0	840
KRTAP26-1	KRTAP20-1	Q3LI63	812
KRTAP26-1	KRTAP20-2	Q3LI61	791
KRTAP26-1	KRTAP6-3	Q3LI67	789
KRTAP26-1	KRTAP6-2	Q3LI66	774
KRTAP26-1	KRTAP15-1	Q3LI76	773
KRTAP26-1	SCYGR1	A0A286YEY9	772
KRTAP26-1	KRTAP6-1	Q3LI64	769
KRTAP26-1	KRTAP25-1	Q3LHN0	769
KRTAP26-1	KRTAP27-1	Q3LI81	720
KRTAP26-1	KRTAP13-3	Q3SY46	697
KRTAP26-1	KRTAP7-1	Q8IUC3	697
KRTAP26-1	KRTAP8-1	Q8IUC2	670
KRTAP26-1	KRTAP13-1	Q8IUC0	663
KRTAP26-1	KRTAP21-1	Q3LI58	624
KRTAP26-1	KRTAP1-4	P0C5Y4	624

IntAct

320 interactions, top by confidence:

A	B	Type	Score
GRN	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.780
KRTAP26-1	GRN	psi-mi:“MI:0915”(physical association)	0.780
KRTAP12-2	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	KRTAP5-6	psi-mi:“MI:0915”(physical association)	0.720
HOXA1	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	KRTAP9-2	psi-mi:“MI:0915”(physical association)	0.720
KRTAP4-2	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	KRTAP12-2	psi-mi:“MI:0915”(physical association)	0.720
KRTAP5-6	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP9-2	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	KRTAP4-2	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	HOXA1	psi-mi:“MI:0915”(physical association)	0.720
KRTAP26-1	CCNJL	psi-mi:“MI:0915”(physical association)	0.670
CCNJL	KRTAP26-1	psi-mi:“MI:0915”(physical association)	0.670
KRTAP26-1	COL8A1	psi-mi:“MI:0915”(physical association)	0.600

BioGRID (104): KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid), KRTAP26-1 (Two-hybrid)

ESM2 similar proteins: A1A580, A2A591, A2A5X4, A2A5X5, A8MUX0, A8MX34, B2RUR4, O13152, O93499, O93500, P02444, P02445, P02446, P02447, P02449, P02450, P02451, P04458, P07521, P08335, P0DV60, P20307, P20308, P25692, P60329, Q24JX8, Q24JX9, Q3LI81, Q3LI83, Q4KL71, Q5T749, Q5T750, Q5TA77, Q6PEX3, Q6R648, Q6S343, Q7TQM5, Q8IUC1, Q92012, Q98U05

Diamond homologs: Q6PEX3, Q9D7N2, A8MUX0, Q3LI83

SIGNOR signaling

0 interactions.

Enriched among interaction partners

Reactome pathways and GO biological processes over-represented among this gene’s 85 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
Keratinization	25	29.0×	2e-29

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	30
Likely benign	2
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

331 predictions. Top by Δscore:

Variant	Effect	Δscore
21:30319552:C:CT	acceptor_gain	0.7400
21:30319819:T:TA	donor_gain	0.7400
21:30319552:C:T	acceptor_gain	0.7300
21:30319584:T:C	acceptor_gain	0.7200
21:30319687:A:AC	donor_gain	0.7200
21:30319688:C:CC	donor_gain	0.7200
21:30319583:C:G	acceptor_gain	0.7000
21:30319754:T:TA	donor_gain	0.6900
21:30319688:CCTCT:C	donor_gain	0.6200
21:30319379:A:AC	donor_gain	0.6100
21:30319380:C:CC	donor_gain	0.6100
21:30319491:C:CC	acceptor_gain	0.6100
21:30319366:A:AC	donor_gain	0.6000
21:30319581:CT:C	acceptor_gain	0.6000
21:30319376:T:C	donor_gain	0.5900
21:30319687:ACCT:A	donor_gain	0.5900
21:30319688:CCTC:C	donor_gain	0.5900
21:30319502:A:AT	donor_gain	0.5800
21:30319584:T:TG	acceptor_gain	0.5600
21:30319431:G:C	acceptor_gain	0.5500
21:30319489:GG:G	acceptor_gain	0.5500
21:30319688:CCT:C	donor_gain	0.5500
21:30319506:TGAAG:T	donor_gain	0.5400
21:30319580:ACTCT:A	acceptor_gain	0.5400
21:30319312:C:CT	donor_gain	0.5300
21:30319313:T:TT	donor_gain	0.5300
21:30320159:T:TA	donor_gain	0.5300
21:30319409:T:TA	donor_gain	0.5200
21:30319463:A:AC	donor_gain	0.5000
21:30319464:C:CC	donor_gain	0.5000

AlphaMissense

1361 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
21:30319745:A:C	F97L	0.726
21:30319745:A:T	F97L	0.726
21:30319747:A:G	F97L	0.726
21:30319493:G:C	S181R	0.619
21:30319493:G:T	S181R	0.619
21:30319495:T:G	S181R	0.619
21:30319436:G:C	F200L	0.614
21:30319436:G:T	F200L	0.614
21:30319438:A:G	F200L	0.614
21:30319466:G:C	F190L	0.572
21:30319466:G:T	F190L	0.572
21:30319468:A:G	F190L	0.572

dbSNP variants (sampled 300 via entrez): RS1000331720 (21:30320624 G>C), RS1001072724 (21:30321010 T>A), RS1001073324 (21:30321974 A>T), RS1001261960 (21:30318767 A>G), RS1002273912 (21:30321963 C>T), RS1002798727 (21:30318789 G>A), RS1002948375 (21:30319740 G>A), RS1003391512 (21:30319945 G>A,T), RS1005112353 (21:30320181 A>T), RS1005323462 (21:30320726 G>T), RS1006326054 (21:30319450 G>A), RS1006858031 (21:30322228 C>T), RS1008445067 (21:30319380 C>G,T), RS1009616178 (21:30322170 A>G), RS1009895487 (21:30320756 A>C,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

4 total (human), top 4 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
CGP 52608	increases reaction, affects binding	1
Benzo(a)pyrene	decreases methylation	1
Valproic Acid	decreases methylation	1
Permethrin	decreases expression	1

Clinical trials (associated diseases)

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