KRTAP2-1

Summary

KRTAP2-1 (keratin associated protein 2-1, HGNC:16775) is a protein-coding gene on chromosome 17q21.2, encoding Keratin-associated protein 2-1 (Q9BYU5). 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 81872 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 31 total
• MANE Select transcript: NM_001123387

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:16775
Approved symbol	KRTAP2-1
Name	keratin associated protein 2-1
Location	17q21.2
Locus type	gene with protein product
Status	Approved
Aliases	KAP2.1A
Ensembl gene	ENSG00000212725
Ensembl biotype	protein_coding
Entrez	81872

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000391419

RefSeq mRNA: 1 — MANE Select: NM_001123387 NM_001123387

CCDS: CCDS42325

Canonical transcript exons

ENST00000391419 — 1 exons

Exon	Start	End
ENSE00001509201	41046541	41047316

Expression profiles

Bgee: expression breadth broad, 53 present calls, max score 45.10.

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
skin of abdomen	UBERON:0001416	45.10	gold quality
zone of skin	UBERON:0000014	42.50	gold quality
right lung	UBERON:0002167	41.66	gold quality
skin of leg	UBERON:0001511	41.02	gold quality
sural nerve	UBERON:0015488	38.17	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
ganglionic eminence	UBERON:0004023	35.49	gold quality
right uterine tube	UBERON:0001302	35.33	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
gastrocnemius	UBERON:0001388	30.55	gold quality
muscle of leg	UBERON:0001383	30.52	gold quality
blood	UBERON:0000178	30.44	gold quality
stromal cell of endometrium	CL:0002255	29.87	gold quality
prefrontal cortex	UBERON:0000451	29.04	gold quality
heart left ventricle	UBERON:0002084	28.98	gold quality
placenta	UBERON:0001987	28.80	gold quality
duodenum	UBERON:0002114	28.14	gold quality
right adrenal gland cortex	UBERON:0035827	27.71	silver quality
lymph node	UBERON:0000029	27.57	gold quality
popliteal artery	UBERON:0002250	27.49	gold quality
kidney	UBERON:0002113	27.44	gold quality
tibial artery	UBERON:0007610	27.32	gold quality
heart	UBERON:0000948	27.28	gold quality
cortex of kidney	UBERON:0001225	27.13	silver quality

Single-cell (SCXA)

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

Experiment	Marker?	Max mean expression
E-ANND-3	no	0.11

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

27 targeting KRTAP2-1, 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-12121	99.99	66.64	255
HSA-MIR-8068	99.98	73.85	2376
HSA-MIR-6721-5P	99.93	68.92	2981
HSA-MIR-7112-5P	99.59	65.76	104
HSA-MIR-6832-5P	99.58	64.82	1132
HSA-MIR-4708-3P	99.51	67.99	870
HSA-MIR-103A-1-5P	99.39	67.78	1545
HSA-MIR-103A-2-5P	99.39	67.72	1577
HSA-MIR-3164	99.02	68.39	1071
HSA-MIR-6820-3P	99.02	68.50	1035
HSA-MIR-3619-5P	99.00	68.87	2308
HSA-MIR-3926	98.95	69.26	1438
HSA-MIR-6871-5P	98.90	66.67	671
HSA-MIR-3145-3P	98.85	69.07	2031
HSA-MIR-3922-5P	98.77	66.53	1059
HSA-MIR-4722-5P	98.46	66.34	1611
HSA-MIR-4773	98.35	67.30	1710
HSA-MIR-499B-5P	98.35	68.39	988
HSA-MIR-5087	98.01	69.09	965
HSA-MIR-9851-5P	97.57	67.49	1067
HSA-MIR-6855-5P	97.51	66.03	830
HSA-MIR-4296	96.35	63.55	1233
HSA-MIR-6742-5P	96.32	64.01	869
HSA-MIR-4265	96.18	64.68	557
HSA-MIR-4322	96.18	64.85	539
HSA-MIR-3170	95.84	64.32	721
HSA-MIR-6796-5P	95.37	66.08	1120

Cross-species orthologs

6 orthologs

Organism	Symbol	Gene ID
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	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), KRTAP4-1 (ENSG00000198443), 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), 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 2-1 — Q9BYU5 (reviewed: Q9BYU5)

Alternative names: High sulfur keratin-associated protein 2.1, Keratin-associated protein 2.1

All UniProt accessions (1): Q9BYU5

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 2 family.

RefSeq proteins (1): NP_001116859* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR002494	KAP	Family
IPR052154	KRTAP_type_2-like	Family

Pfam: PF01500

UniProt features (2 total): chain 1, region of interest 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q9BYU5-F1	34.34	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: 15 (showing top): GOCC_INTERMEDIATE_FILAMENT_CYTOSKELETON, GOCC_KERATIN_FILAMENT, GOCC_SUPRAMOLECULAR_COMPLEX, GOCC_POLYMERIC_CYTOSKELETAL_FIBER, ZWANG_TRANSIENTLY_UP_BY_2ND_EGF_PULSE_ONLY, BCAT_BILD_ET_AL_UP, E2F3_UP.V1_DN, MYC_UP.V1_DN, REACTOME_KERATINIZATION, GOCC_SUPRAMOLECULAR_POLYMER, MIR3145_3P, MIR4773, GSE17974_IL4_AND_ANTI_IL12_VS_UNTREATED_48H_ACT_CD4_TCELL_UP, GSE21927_SPLENIC_C26GM_TUMOROUS_VS_4T1_TUMOR_MONOCYTES_UP, chr17q21

GO Biological Process (0):

GO Molecular Function (0):

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
cytoplasm	1
cellular anatomical structure	1
intermediate filament	1
intermediate filament cytoskeleton	1
polymeric cytoskeletal fiber	1

Protein interactions and networks

STRING

252 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
KRTAP2-1	KRTAP13-3	Q3SY46	623
KRTAP2-1	KRTAP24-1	Q3LI83	603
KRTAP2-1	ARHGEF33	A8MVX0	545
KRTAP2-1	KRTAP1-4	P0C5Y4	544
KRTAP2-1	FRMD1	Q8N878	506
KRTAP2-1	SPRR4	Q96PI1	500
KRTAP2-1	KRTAP3-2	Q9BYR7	480
KRTAP2-1	KRTAP15-1	Q3LI76	464
KRTAP2-1	KRTAP8-1	Q8IUC2	447
KRTAP2-1	KRTAP11-1	Q8IUC1	446
KRTAP2-1	PAGE1	O75459	433
KRTAP2-1	RNF169	Q8NCN4	423
KRTAP2-1	KRTAP3-1	Q9BYR8	416
KRTAP2-1	DAOA	P59103	400
KRTAP2-1	DCLK3	Q9C098	399

IntAct

0 interactions, top by confidence:

ESM2 similar proteins: A5A6P5, A6QP35, A8MTY7, A8MVA2, A8MXZ3, O75690, P02438, P02441, P02442, P02443, P08131, P0C7H8, P26371, P59990, P59991, P60014, P60331, P60368, P60369, P60370, P60371, P60372, P60409, P60410, P60411, P60412, P60413, Q05B44, Q07627, Q3V2C1, Q6L8G4, Q6L8G8, Q6L8G9, Q6L8H2, Q701N4, Q8IUG1, Q9BQ66, Q9BYP9, Q9BYQ0, Q9BYQ2

Diamond homologs: P02441, P02442, P02443, P0C7H8, Q9BYR9, Q9BYT5, Q9BYU5

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	30
Likely benign	1
Benign	0

Top pathogenic / likely-pathogenic (0)

SpliceAI

147 predictions. Top by Δscore:

Variant	Effect	Δscore
17:41047056:T:A	donor_gain	0.9100
17:41047226:G:C	donor_gain	0.6800
17:41047081:A:T	donor_gain	0.6500
17:41046544:T:C	acceptor_gain	0.6200
17:41046544:T:TC	acceptor_gain	0.6200
17:41046895:T:TA	donor_gain	0.5900
17:41047003:A:T	donor_gain	0.5800
17:41046717:T:TC	acceptor_gain	0.5700
17:41046884:G:C	donor_gain	0.5600
17:41047219:C:A	donor_gain	0.5600
17:41046717:T:C	acceptor_gain	0.5500
17:41047085:C:CT	donor_gain	0.5500
17:41047218:C:A	donor_gain	0.5500
17:41046623:CAGA:C	donor_gain	0.5300
17:41047086:G:T	donor_gain	0.5300
17:41047082:C:T	donor_gain	0.5200
17:41046954:TG:T	donor_gain	0.5100
17:41047000:TGCA:T	donor_gain	0.5100
17:41047006:C:CT	donor_gain	0.5100
17:41046626:A:AC	donor_gain	0.5000
17:41046627:C:CC	donor_gain	0.5000
17:41046570:T:TC	acceptor_gain	0.4900
17:41046594:T:C	donor_gain	0.4500
17:41046616:T:TA	donor_gain	0.4500
17:41046805:T:TA	donor_gain	0.4500
17:41046553:C:CT	acceptor_gain	0.4400
17:41046585:G:A	donor_gain	0.4400
17:41046598:A:AC	donor_gain	0.4400
17:41046629:T:TA	donor_gain	0.4400
17:41046849:TG:T	donor_gain	0.4400

AlphaMissense

814 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
17:41047003:A:G	C89R	0.948
17:41047001:G:C	C89W	0.929
17:41046986:C:A	W94C	0.928
17:41046986:C:G	W94C	0.928
17:41047033:A:G	C79R	0.918
17:41047002:C:T	C89Y	0.903
17:41047038:A:G	I77T	0.903
17:41047038:A:T	I77N	0.899
17:41047038:A:C	I77S	0.897
17:41047002:C:G	C89S	0.892
17:41047003:A:T	C89S	0.892
17:41047031:G:C	C79W	0.892
17:41046988:A:G	W94R	0.880
17:41046988:A:T	W94R	0.880
17:41047155:G:A	T38I	0.877
17:41047018:A:G	C84R	0.872
17:41047054:C:G	G72R	0.872
17:41047028:G:C	C80W	0.870
17:41046991:A:G	C93R	0.867
17:41046989:G:C	C93W	0.862
17:41046992:G:C	C92W	0.859
17:41046996:G:T	P91H	0.857
17:41047048:A:G	C74R	0.854
17:41047051:A:G	C73R	0.853
17:41047079:G:C	C63W	0.848
17:41047046:G:C	C74W	0.842
17:41046999:C:A	R90M	0.841
17:41047067:G:C	C67W	0.837
17:41047081:A:G	C63R	0.837
17:41047032:C:T	C79Y	0.835

dbSNP variants (sampled 300 via entrez): RS1000840289 (17:41047125 G>C), RS1002838622 (17:41049188 T>G), RS1005526399 (17:41049171 C>T), RS1005654424 (17:41047343 C>A,G,T), RS1006032495 (17:41048798 C>A,T), RS1006086508 (17:41049064 G>A), RS1006377094 (17:41046525 T>A,C,G), RS1007061681 (17:41046267 T>C), RS1007822064 (17:41047450 T>C,G), RS1008376336 (17:41048791 A>G), RS1008639179 (17:41047102 C>A), RS1009080942 (17:41048548 A>G), RS1009588202 (17:41047179 C>T), RS1009826706 (17:41048503 G>T), RS1011062649 (17:41046523 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

12 total (human), top 12 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
bisphenol A	affects expression, decreases expression	2
Benzo(a)pyrene	affects methylation	2
Ethinyl Estradiol	affects expression, decreases expression	2
Smoke	increases expression	2
tricetin	increases expression	1
Resveratrol	affects cotreatment, decreases expression	1
Fulvestrant	increases methylation	1
Curcumin	decreases expression	1
Formaldehyde	decreases expression	1
Plant Extracts	affects cotreatment, decreases expression	1
Rotenone	increases expression	1
Aflatoxin B1	decreases methylation	1

Clinical trials (associated diseases)

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