KRTAP4-16

Summary

KRTAP4-16 (keratin associated protein 4-16, HGNC:18921) is a protein-coding gene on chromosome 17q21.2, encoding Keratin-associated protein 4-16 (G5E9R7). 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 and keratin filament.

Source: NCBI Gene 85354 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 2 total
• MANE Select transcript: NM_001396067

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:18921
Approved symbol	KRTAP4-16
Name	keratin associated protein 4-16
Location	17q21.2
Locus type	gene with protein product
Status	Approved
Aliases	KAP4A
Ensembl gene	ENSG00000241241
Ensembl biotype	protein_coding
Entrez	85354

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000440582

RefSeq mRNA: 1 — MANE Select: NM_001396067 NM_001396067

CCDS: CCDS92304

Canonical transcript exons

ENST00000440582 — 1 exons

Exon	Start	End
ENSE00001674047	41101502	41102209

Expression profiles

Bgee: expression breadth tissue_specific, 3 present calls, max score 37.20.

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	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
sural nerve	UBERON:0015488	30.93	gold quality
stromal cell of endometrium	CL:0002255	29.87	gold quality
liver	UBERON:0002107	28.56	gold quality
duodenum	UBERON:0002114	28.14	gold quality
olfactory segment of nasal mucosa	UBERON:0005386	27.71	silver 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
leukocyte	CL:0000738	26.24	gold quality
blood	UBERON:0000178	26.16	gold quality
monocyte	CL:0000576	26.10	gold quality
gall bladder	UBERON:0002110	25.98	gold quality
placenta	UBERON:0001987	25.81	gold quality
urinary bladder	UBERON:0001255	25.72	gold quality
muscle of leg	UBERON:0001383	24.88	gold quality
primary visual cortex	UBERON:0002436	24.61	gold quality
superior frontal gyrus	UBERON:0002661	24.08	gold quality
pancreas	UBERON:0001264	24.02	gold quality
cortex of kidney	UBERON:0001225	23.71	gold quality
gastrocnemius	UBERON:0001388	23.66	gold quality

Single-cell (SCXA)

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

Experiment	Marker?	Max mean expression
E-ANND-3	no	0.30

Regulation

Is transcription factor: no

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), 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)

Protein

Protein identifiers

Keratin-associated protein 4-16 — G5E9R7 (reviewed: G5E9R7)

All UniProt accessions (1): G5E9R7

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.

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_001382996* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR002494	KAP	Family

Pfam: PF13885

UniProt features (20 total): repeat 16, region of interest 2, chain 1, compositionally biased region 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-G5E9R7-F1	45.15	0.00

Function

Pathways and Gene Ontology

Reactome pathways

0 pathways

MSigDB gene sets: 7 (showing top): GOBP_MOLTING_CYCLE, GOCC_INTERMEDIATE_FILAMENT_CYTOSKELETON, GOCC_KERATIN_FILAMENT, GOCC_SUPRAMOLECULAR_COMPLEX, GOCC_POLYMERIC_CYTOSKELETAL_FIBER, GOCC_SUPRAMOLECULAR_POLYMER, chr17q21

GO Biological Process (1): hair cycle (GO:0042633)

GO Molecular Function (0):

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

GO top-level categories

Rollup of top GO terms by namespace:

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

Protein interactions and networks

STRING

62 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
KRTAP4-16	KRTAP21-1	Q3LI58	627
KRTAP4-16	DNASE1L2	Q92874	448
KRTAP4-16	KRT83	P78385	446
KRTAP4-16	KRT27	Q7Z3Y8	420
KRTAP4-16	KRT25	Q7Z3Z0	417
KRTAP4-16	KRT71	Q3SY84	413
KRTAP4-16	GPRC5D	Q9NZD1	399
KRTAP4-16	DSG4	Q86SJ6	391
KRTAP4-16	SOX21	P35715	307
KRTAP4-16	ALX4	Q9H161	307
KRTAP4-16	HOXC13	P31276	305
KRTAP4-16	FOXQ1	Q9C009	287
KRTAP4-16	PRR9	Q5T870	277
KRTAP4-16	VSIG8	P0DPA2	270
KRTAP4-16	VANGL2	Q9ULK5	269

IntAct

0 interactions, top by confidence:

ESM2 similar proteins: A2A591, A2A5X4, A2A5X5, A8MUX0, A8MX34, B2RUR4, G5E9R7, O13152, O93499, O93500, P02438, P02439, P02440, P02445, P02449, P02451, P04458, P07521, P08131, P08335, P60329, Q24JX8, Q24JX9, Q3LI83, Q4KL71, Q5T749, Q5T750, Q64298, Q67UU9, Q6PEX3, Q6R648, Q7TQM5, Q8BV84, Q8IUC1, Q92012, Q98U05, Q9BYQ7, Q9BYQ8, Q9BYQ9, Q9BYR0

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

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

Top pathogenic / likely-pathogenic (0)

SpliceAI

93 predictions. Top by Δscore:

Variant	Effect	Δscore
17:41101984:T:TA	donor_gain	0.8600
17:41101964:G:C	donor_gain	0.7300
17:41101803:CG:C	donor_gain	0.7200
17:41101961:G:C	donor_gain	0.7000
17:41101956:A:T	donor_gain	0.6700
17:41101933:A:AC	donor_gain	0.6600
17:41101934:C:CC	donor_gain	0.6600
17:41101530:C:CC	acceptor_gain	0.6500
17:41101528:CA:C	acceptor_gain	0.6100
17:41102168:A:AC	donor_gain	0.6100
17:41102169:C:CC	donor_gain	0.6100
17:41101949:G:C	donor_gain	0.5600
17:41101958:A:AC	donor_gain	0.5400
17:41101959:C:CC	donor_gain	0.5400
17:41101959:CAG:C	donor_gain	0.5300
17:41102002:G:T	donor_gain	0.5300
17:41101525:TAACA:T	acceptor_gain	0.5200
17:41101526:AACA:A	acceptor_gain	0.4800
17:41101527:ACA:A	acceptor_gain	0.4700
17:41101528:CAC:C	acceptor_gain	0.4700
17:41102009:G:C	donor_gain	0.4700
17:41102053:A:AC	donor_gain	0.4700
17:41102054:C:CC	donor_gain	0.4700
17:41101802:TCGAC:T	donor_gain	0.4500
17:41101803:CGACC:C	donor_gain	0.4500
17:41101889:G:C	donor_gain	0.4500
17:41101529:ACT:A	acceptor_loss	0.4200
17:41101531:T:A	acceptor_loss	0.4200
17:41102069:G:C	donor_gain	0.4200
17:41102082:CAG:C	acceptor_gain	0.4000

AlphaMissense

1535 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
17:41101761:A:G	I150T	0.751
17:41102069:G:C	S47R	0.632
17:41102069:G:T	S47R	0.632
17:41102071:T:G	S47R	0.632
17:41101761:A:C	I150S	0.624
17:41101949:G:C	S87R	0.618
17:41101949:G:T	S87R	0.618
17:41101951:T:G	S87R	0.618
17:41101761:A:T	I150N	0.595
17:41101679:G:C	F177L	0.580
17:41101679:G:T	F177L	0.580
17:41101681:A:G	F177L	0.580
17:41101764:A:T	V149D	0.574

dbSNP variants (sampled 300 via entrez): RS1000704701 (17:41103452 G>A), RS1002746857 (17:41101468 C>G,T), RS1005616353 (17:41102423 G>A,C,T), RS1007336617 (17:41104098 A>C), RS1011351034 (17:41101499 G>A,C), RS1011403497 (17:41101821 A>C,G), RS1015127313 (17:41102202 C>G,T), RS1015281724 (17:41101178 G>A), RS1016538775 (17:41102431 A>G), RS1019755453 (17:41101876 T>C), RS1021816443 (17:41101509 A>AGCAT), RS1023046407 (17:41103204 T>C), RS1023561008 (17:41103434 A>C), RS1025433256 (17:41103993 A>G), RS1025485614 (17:41104142 G>A,T)

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)

Clinical trials (associated diseases)

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