KRTAP20-1

Summary

KRTAP20-1 (keratin associated protein 20-1, HGNC:18943) is a protein-coding gene on chromosome 21q22.11, encoding Keratin-associated protein 20-1 (Q3LI63). 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 be located in cytosol.

Source: NCBI Gene 337975 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 8 total
• MANE Select transcript: NM_181615

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:18943
Approved symbol	KRTAP20-1
Name	keratin associated protein 20-1
Location	21q22.11
Locus type	gene with protein product
Status	Approved
Aliases	KAP20.1
Ensembl gene	ENSG00000244624
Ensembl biotype	protein_coding
Entrez	337975

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000334664

RefSeq mRNA: 1 — MANE Select: NM_181615 NM_181615

CCDS: CCDS13603

Canonical transcript exons

ENST00000334664 — 1 exons

Exon	Start	End
ENSE00001337800	30616425	30616699

Expression profiles

Bgee: expression breadth broad, 28 present calls, max score 38.07.

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
sural nerve	UBERON:0015488	38.07	silver 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
ganglionic eminence	UBERON:0004023	35.49	gold quality
skeletal muscle tissue	UBERON:0001134	33.38	gold quality
hindlimb stylopod muscle	UBERON:0004252	32.15	gold quality
bone marrow	UBERON:0002371	31.74	gold quality
muscle tissue	UBERON:0002385	31.06	gold quality
stromal cell of endometrium	CL:0002255	29.87	gold quality
prefrontal cortex	UBERON:0000451	29.04	gold quality
duodenum	UBERON:0002114	28.14	gold quality
urinary bladder	UBERON:0001255	28.10	silver quality
liver	UBERON:0002107	28.04	gold quality
monocyte	CL:0000576	27.82	gold quality
leukocyte	CL:0000738	27.80	gold quality
lymph node	UBERON:0000029	27.57	gold quality
tonsil	UBERON:0002372	27.05	gold quality
islet of Langerhans	UBERON:0000006	26.55	gold quality
vermiform appendix	UBERON:0001154	26.42	gold quality
blood	UBERON:0000178	26.26	silver quality
gall bladder	UBERON:0002110	25.98	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	25.89	gold quality
placenta	UBERON:0001987	25.81	gold quality
primary visual cortex	UBERON:0002436	24.61	gold quality
fundus of stomach	UBERON:0001160	24.49	gold quality
skin of abdomen	UBERON:0001416	24.25	gold quality
superior frontal gyrus	UBERON:0002661	24.08	gold quality
frontal cortex	UBERON:0001870	23.88	gold quality

Single-cell (SCXA)

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

Experiment	Marker?	Max mean expression
E-ANND-3	no	0.98

Regulation

Is transcription factor: no

Cross-species orthologs

0 orthologs

Protein

Protein identifiers

Keratin-associated protein 20-1 — Q3LI63 (reviewed: Q3LI63)

All UniProt accessions (1): Q3LI63

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.

Similarity. Belongs to the KRTAP type 20 family.

RefSeq proteins (1): NP_853646* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR021743	KRTAP_type8/19/20/21/22	Family
IPR052878	KRTAP_matrix	Family

Pfam: PF11759

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

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q3LI63-F1	47.05	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: 12 (showing top): MARTINEZ_RB1_TARGETS_DN, WTGAAAT_UNKNOWN, chr21q22, ACEVEDO_LIVER_CANCER_WITH_H3K27ME3_DN, GOCC_INTERMEDIATE_FILAMENT_CYTOSKELETON, GOCC_SUPRAMOLECULAR_COMPLEX, GOCC_POLYMERIC_CYTOSKELETAL_FIBER, REACTOME_KERATINIZATION, GOCC_SUPRAMOLECULAR_POLYMER, MARTINEZ_RB1_AND_TP53_TARGETS_DN, MARTINEZ_TP53_TARGETS_DN, GSE32034_UNTREATED_VS_ROSIGLIZATONE_TREATED_LY6C_LOW_MONOCYTE_UP

GO Biological Process (0):

GO Molecular Function (0):

GO Cellular Component (2): cytosol (GO:0005829), 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
cytoplasm	1
cellular anatomical structure	1
intermediate filament cytoskeleton	1
polymeric cytoskeletal fiber	1

Protein interactions and networks

STRING

128 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
KRTAP20-1	KRTAP15-1	Q3LI76	883
KRTAP20-1	KRTAP22-1	Q3MIV0	881
KRTAP20-1	SCYGR1	A0A286YEY9	874
KRTAP20-1	KRTAP24-1	Q3LI83	871
KRTAP20-1	KRTAP6-3	Q3LI67	870
KRTAP20-1	KRTAP26-1	Q6PEX3	812
KRTAP20-1	KRTAP13-3	Q3SY46	795
KRTAP20-1	KRTAP6-1	Q3LI64	791
KRTAP20-1	KRTAP7-1	Q8IUC3	780
KRTAP20-1	KRTAP27-1	Q3LI81	771
KRTAP20-1	KRTAP6-2	Q3LI66	764
KRTAP20-1	KRTAP8-1	Q8IUC2	761
KRTAP20-1	KRTAP13-1	Q8IUC0	748
KRTAP20-1	KRTAP11-1	Q8IUC1	711
KRTAP20-1	KRTAP21-1	Q3LI58	667

IntAct

0 interactions, top by confidence:

ESM2 similar proteins: H2A0M6, O08632, O08633, O08640, P02448, P04459, P05685, P08826, P25692, P82170, P83358, Q02957, Q02958, Q28580, Q3LHN2, Q3LI54, Q3LI58, Q3LI59, Q3LI60, Q3LI61, Q3LI63, Q3LI64, Q3LI66, Q3LI67, Q3LI68, Q3LI70, Q3LI72, Q3LI73, Q3LI77, Q3MIV0, Q3SYF9, Q4W7G7, Q4W7G8, Q4W7G9, Q4W7H0, Q4W7H1, Q6F4C6, Q6R645, Q7Z4W3, Q8C1I6

Diamond homologs: Q3LI61, Q3LI63, Q3LI72, Q3SYF9

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	8
Likely benign	0
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

99 predictions. Top by Δscore:

Variant	Effect	Δscore
21:30616483:GCTA:G	donor_gain	0.7300
21:30616597:G:GT	donor_gain	0.6500
21:30616481:T:TA	donor_gain	0.6400
21:30616484:C:G	donor_gain	0.6400
21:30616482:G:GA	donor_gain	0.5800
21:30616490:G:GG	donor_gain	0.5700
21:30616478:T:A	donor_gain	0.5400
21:30616480:GTGGC:G	donor_gain	0.5300
21:30616483:G:GG	donor_gain	0.5200
21:30616488:GG:G	donor_gain	0.5200
21:30616489:GG:G	donor_gain	0.5200
21:30616610:A:AG	donor_gain	0.4900
21:30616601:A:G	donor_gain	0.4700
21:30616482:GGCTA:G	donor_gain	0.4500
21:30616485:TATGG:T	donor_loss	0.4500
21:30616486:ATGG:A	donor_loss	0.4500
21:30616487:TGG:T	donor_loss	0.4500
21:30616488:GGG:G	donor_loss	0.4500
21:30616490:GTAT:G	donor_loss	0.4500
21:30616491:T:C	donor_loss	0.4500
21:30616492:A:C	donor_loss	0.4400
21:30616597:G:T	donor_gain	0.4400
21:30616633:TAGAG:T	acceptor_gain	0.4300
21:30616592:C:G	donor_gain	0.4200
21:30616646:A:G	donor_gain	0.4100
21:30616607:GTCA:G	donor_gain	0.4000
21:30616608:TCAT:T	donor_gain	0.4000
21:30616567:G:GT	donor_gain	0.3900
21:30616553:C:G	donor_gain	0.3800
21:30616609:C:A	donor_gain	0.3800

AlphaMissense

339 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
21:30616617:T:C	F55L	0.895
21:30616619:C:A	F55L	0.895
21:30616619:C:G	F55L	0.895
21:30616620:T:G	Y56D	0.574

dbSNP variants (sampled 300 via entrez): RS1001092125 (21:30615888 A>T), RS1002741151 (21:30615841 G>A), RS1006093814 (21:30615170 G>A), RS1006454122 (21:30615430 G>A,C), RS1007711429 (21:30617069 C>T), RS1008180217 (21:30616672 C>T), RS1008436894 (21:30615321 G>A), RS1009015718 (21:30615593 C>T), RS1010360156 (21:30616848 G>A), RS1010371440 (21:30616508 T>C), RS1011048021 (21:30614755 A>G), RS1013293883 (21:30614881 T>C), RS1013882259 (21:30616409 T>A,C), RS1014349991 (21:30616098 G>A), RS1015996615 (21:30616720 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

6 total (human), top 6 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
polyhexamethyleneguanidine	affects expression	1
CGP 52608	affects binding, increases reaction	1
Benzo(a)pyrene	affects methylation	1
Cadmium	increases abundance, decreases expression	1
Aflatoxin B1	decreases methylation	1
Cadmium Chloride	decreases expression, increases abundance	1

Clinical trials (associated diseases)

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