TJAP1

Summary

TJAP1 (tight junction associated protein 1, HGNC:17949) is a protein-coding gene on chromosome 6p21.1, encoding Tight junction-associated protein 1 (Q5JTD0). Plays a role in regulating the structure of the Golgi apparatus.

This gene encodes a tight junction-associated protein. Incorporation of the encoded protein into tight junctions occurs at a late stage of formation of the junctions. The encoded protein localizes to the Golgi and may function in vesicle trafficking. Alternatively spliced transcript variants have been described. A related pseudogene exists on the X chromosome.

Source: NCBI Gene 93643 — RefSeq curated summary.

At a glance

• GWAS associations: 5
• Clinical variants (ClinVar): 98 total — 1 pathogenic
• MANE Select transcript: NM_001350562

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:17949
Approved symbol	TJAP1
Name	tight junction associated protein 1
Location	6p21.1
Locus type	gene with protein product
Status	Approved
Aliases	PILT
Ensembl gene	ENSG00000137221
Ensembl biotype	protein_coding
OMIM	612658
Entrez	93643

Gene structure

Transcript identifiers

Ensembl transcripts: 76 — 71 protein_coding, 5 protein_coding_CDS_not_defined

ENST00000259751, ENST00000372444, ENST00000372445, ENST00000372449, ENST00000372452, ENST00000372454, ENST00000436109, ENST00000438588, ENST00000442878, ENST00000454762, ENST00000459851, ENST00000478173, ENST00000483640, ENST00000490050, ENST00000612912, ENST00000871108, ENST00000871109, ENST00000871110, ENST00000871111, ENST00000871112, ENST00000871113, ENST00000871114, ENST00000871115, ENST00000871116, ENST00000871117, ENST00000871118, ENST00000871119, ENST00000871120, ENST00000871121, ENST00000871122, ENST00000871123, ENST00000871124, ENST00000871125, ENST00000871126, ENST00000871127, ENST00000871128, ENST00000871129, ENST00000871130, ENST00000871131, ENST00000871132, ENST00000871133, ENST00000871134, ENST00000871135, ENST00000871136, ENST00000871137, ENST00000871138, ENST00000871139, ENST00000871140, ENST00000871141, ENST00000871142, ENST00000871143, ENST00000871144, ENST00000871145, ENST00000871146, ENST00000871147, ENST00000871148, ENST00000871149, ENST00000871150, ENST00000871151, ENST00000926275, ENST00000926276, ENST00000926277, ENST00000926278, ENST00000926279, ENST00000926280, ENST00000926281, ENST00000969270, ENST00000969271, ENST00000969272, ENST00000969273, ENST00000969274, ENST00000969275, ENST00000969276, ENST00000969277, ENST00000969278, ENST00000969279

RefSeq mRNA: 24 — MANE Select: NM_001350562 NM_001146016, NM_001146017, NM_001146018, NM_001146019, NM_001146020, NM_001350561, NM_001350562, NM_001350563, NM_001350564, NM_001350565, NM_001350566, NM_001350567, NM_001350568, NM_001350569, NM_001350570, NM_001394538, NM_001394539, NM_001394540, NM_001394541, NM_001394542, NM_001394543, NM_001394544, NM_001394545, NM_080604

CCDS: CCDS4898, CCDS55004

Canonical transcript exons

ENST00000372449 — 11 exons

Exon	Start	End
ENSE00001037681	43497881	43497977
ENSE00001037694	43478087	43478232
ENSE00001457831	43502588	43502617
ENSE00001457854	43498978	43499100
ENSE00003477631	43500744	43500772
ENSE00003536081	43501526	43501687
ENSE00003550953	43502283	43502349
ENSE00003628631	43503401	43503508
ENSE00003791263	43503623	43503706
ENSE00003978122	43504761	43506554
ENSE00003978123	43477570	43477628

Expression profiles

Bgee: expression breadth ubiquitous, 277 present calls, max score 98.93.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 22.6124 / max 217.0966, expressed in 1818 samples.

FANTOM5 promoters (6 alternative TSS)

Promoter ID	TPM avg	Samples expressed
67907	21.9166	1818
67911	0.3030	67
67908	0.2662	67
67910	0.0858	39
67909	0.0288	17
204001	0.0121	5

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
secondary oocyte	CL:0000655	98.93	gold quality
oocyte	CL:0000023	97.33	gold quality
sural nerve	UBERON:0015488	96.52	gold quality
C1 segment of cervical spinal cord	UBERON:0006469	94.54	gold quality
inferior vagus X ganglion	UBERON:0005363	94.38	gold quality
spinal cord	UBERON:0002240	93.81	gold quality
cranial nerve II	UBERON:0000941	93.32	gold quality
inferior olivary complex	UBERON:0002127	92.76	gold quality
left ovary	UBERON:0002119	92.58	gold quality
gastrocnemius	UBERON:0001388	92.53	gold quality
right ovary	UBERON:0002118	92.31	gold quality
body of uterus	UBERON:0009853	92.05	gold quality
muscle of leg	UBERON:0001383	91.90	gold quality
tibial nerve	UBERON:0001323	91.87	gold quality
right lobe of thyroid gland	UBERON:0001119	91.77	gold quality
right adrenal gland	UBERON:0001233	91.75	gold quality
right uterine tube	UBERON:0001302	91.75	gold quality
mucosa of stomach	UBERON:0001199	91.56	gold quality
granulocyte	CL:0000094	91.53	gold quality
right adrenal gland cortex	UBERON:0035827	91.52	gold quality
esophagogastric junction muscularis propria	UBERON:0035841	91.27	gold quality
muscle layer of sigmoid colon	UBERON:0035805	91.23	gold quality
left adrenal gland	UBERON:0001234	91.22	gold quality
left adrenal gland cortex	UBERON:0035825	91.22	gold quality
ovary	UBERON:0000992	91.21	gold quality
left lobe of thyroid gland	UBERON:0001120	91.20	gold quality
lower esophagus muscularis layer	UBERON:0035833	91.19	gold quality
lower esophagus	UBERON:0013473	91.15	gold quality
apex of heart	UBERON:0002098	91.04	gold quality
adrenal cortex	UBERON:0001235	90.90	gold quality

Single-cell (SCXA)

Detected in 2 experiment(s), a significant marker in 1.

Experiment	Marker?	Max mean expression
E-ANND-3	yes	3.44
E-GEOD-81383	no	48.48

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

36 targeting TJAP1, 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-520G-5P	99.99	66.76	658
HSA-MIR-4650-5P	99.98	64.69	999
HSA-MIR-22-3P	99.93	68.13	917
HSA-MIR-4496	99.88	68.89	2236
HSA-MIR-4492	99.87	68.25	3611
HSA-MIR-765	99.84	68.24	2442
HSA-MIR-4319	99.76	69.83	2586
HSA-MIR-11181-3P	99.75	66.38	2205
HSA-MIR-132-3P	99.73	70.56	1424
HSA-MIR-212-3P	99.73	70.65	1424
HSA-MIR-545-5P	99.66	70.18	2308
HSA-MIR-488-3P	99.61	68.79	1731
HSA-MIR-762	99.58	66.61	1994
HSA-MIR-4498	99.47	67.42	2360
HSA-MIR-766-5P	99.47	67.91	2225
HSA-MIR-2392	99.43	67.50	708
HSA-MIR-10522-5P	99.26	68.50	2087
HSA-MIR-4263	99.18	69.25	2236
HSA-MIR-5001-5P	99.05	66.76	1972
HSA-MIR-194-5P	99.01	69.65	1465
HSA-MIR-6829-5P	98.86	65.12	1480
HSA-MIR-4656	98.79	66.22	1306
HSA-MIR-655-5P	98.74	65.93	888
HSA-MIR-5008-5P	98.42	65.87	1019
HSA-MIR-4782-5P	98.35	69.33	1474
HSA-MIR-5706	98.35	69.33	1463
HSA-MIR-92A-1-5P	98.28	64.51	631
HSA-MIR-4741	97.69	64.14	883
HSA-MIR-4675	97.69	64.82	774
HSA-MIR-3144-5P	97.64	65.45	646

Cross-species orthologs

1 orthologs

Organism	Symbol	Gene ID
mus_musculus	Tjap1	ENSMUSG00000012296

Protein

Protein identifiers

Tight junction-associated protein 1 — Q5JTD0 (reviewed: Q5JTD0)

Alternative names: Protein incorporated later into tight junctions, Tight junction protein 4

All UniProt accessions (4): Q5JTD0, A0A075B6G8, E2QRK7, H0Y4D6

UniProt curated annotations — full annotation on UniProt →

Function. Plays a role in regulating the structure of the Golgi apparatus.

Subunit / interactions. Interacts with DLG1. Interacts with ARF6 (GTP-bound form).

Subcellular location. Golgi apparatus. trans-Golgi network. Cell junction. Tight junction. Cell membrane.

Tissue specificity. Ubiquitously expressed.

Isoforms (4)

UniProt ID	Names	Canonical?
Q5JTD0-1	1	yes
Q5JTD0-2	2
Q5JTD0-3	3
Q5JTD0-4	4

RefSeq proteins (24): NP_001139488, NP_001139489, NP_001139490, NP_001139491, NP_001139492, NP_001337490, NP_001337491, NP_001337492, NP_001337493, NP_001337494, NP_001337495, NP_001337496, NP_001337497, NP_001337498, NP_001337499, NP_001381467, NP_001381468, NP_001381469, NP_001381470, NP_001381471, NP_001381472, NP_001381473, NP_001381474, NP_542171 (=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR043441	Tjap1/BEGAIN	Family
IPR043470	Tjap1_dom	Domain

Pfam: PF15453

UniProt features (30 total): compositionally biased region 8, modified residue 8, region of interest 5, splice variant 4, sequence conflict 2, initiator methionine 1, chain 1, coiled-coil region 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-Q5JTD0-F1	63.11	0.26

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Post-translational modifications (8): 2, 300, 318, 320, 345, 422, 491, 545

Function

Pathways and Gene Ontology

Reactome pathways

0 pathways

MSigDB gene sets: 122 (showing top): GCM_MAP4K4, GCANCTGNY_MYOD_Q6, KEGG_TIGHT_JUNCTION, TAL1ALPHAE47_01, YY1_Q6, CTCTAGA_MIR526C_MIR518F_MIR526A, NFKB_C, GOCC_TRANS_GOLGI_NETWORK, BLALOCK_ALZHEIMERS_DISEASE_UP, GOBP_ENDOMEMBRANE_SYSTEM_ORGANIZATION, CCCNNNNNNAAGWT_UNKNOWN, IK3_01, GOCC_CELL_CELL_JUNCTION, TAL1BETAE47_01, TGGAAA_NFAT_Q4_01

GO Biological Process (1): Golgi organization (GO:0007030)

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

GO Cellular Component (8): endosome (GO:0005768), Golgi apparatus (GO:0005794), trans-Golgi network (GO:0005802), plasma membrane (GO:0005886), bicellular tight junction (GO:0005923), cytoplasm (GO:0005737), membrane (GO:0016020), anchoring junction (GO:0070161)

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
endomembrane system	2
cellular anatomical structure	2
organelle organization	1
endomembrane system organization	1
binding	1
cytoplasmic vesicle	1
cytoplasm	1
intracellular membrane-bounded organelle	1
Golgi apparatus subcompartment	1
membrane	1
cell periphery	1
apical junction complex	1
tight junction	1
intracellular anatomical structure	1
cell junction	1

Protein interactions and networks

STRING

824 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
TJAP1	DXO	O77932	901
TJAP1	MPP2	Q14168	849
TJAP1	DLG2	Q15700	796
TJAP1	DNASE1L2	Q92874	766
TJAP1	XRN2	Q9H0D6	736
TJAP1	F11R	Q9Y624	668
TJAP1	ERI2	A8K979	648
TJAP1	SMG6	Q86US8	624
TJAP1	MSRB2	Q9Y3D2	621
TJAP1	CLDN1	O95832	591
TJAP1	SMG5	Q9UPR3	581
TJAP1	SMG7	Q92540	570
TJAP1	DIS3	Q9Y2L1	570
TJAP1	SKIC2	Q15477	555
TJAP1	DCP2	Q8IU60	536

IntAct

42 interactions, top by confidence:

A	B	Type	Score
APBA2	APP	psi-mi:“MI:0914”(association)	0.690
APBA1	LIN7A	psi-mi:“MI:0914”(association)	0.590
KRT75	TJAP1	psi-mi:“MI:0915”(physical association)	0.560
TJAP1	TRIM54	psi-mi:“MI:0915”(physical association)	0.560
TJAP1	MEOX2	psi-mi:“MI:0915”(physical association)	0.560
GOLGA6L9	TJAP1	psi-mi:“MI:0915”(physical association)	0.560
APBA3	DUSP11	psi-mi:“MI:0914”(association)	0.530
APBA2	HERC2	psi-mi:“MI:0914”(association)	0.530
APBA3	CLSTN1	psi-mi:“MI:0914”(association)	0.530
TJAP1	DLG4	psi-mi:“MI:0915”(physical association)	0.370
Xpo1	IFT56	psi-mi:“MI:0914”(association)	0.350
M		psi-mi:“MI:0914”(association)	0.350
CORO1A	RABGAP1L	psi-mi:“MI:0914”(association)	0.350
SYCE1	RABGAP1L	psi-mi:“MI:0914”(association)	0.350
APBA1	KIF2A	psi-mi:“MI:0914”(association)	0.350
SYNC	NDC80	psi-mi:“MI:0914”(association)	0.350
FHL3	COBL	psi-mi:“MI:0914”(association)	0.350
FHL3		psi-mi:“MI:0914”(association)	0.350
CORO1A	PSMD9	psi-mi:“MI:0914”(association)	0.350
SYNC	MAP3K7	psi-mi:“MI:0914”(association)	0.350
DLG3	KIF1B	psi-mi:“MI:0914”(association)	0.350
BET1	ESYT2	psi-mi:“MI:2364”(proximity)	0.270
LAMP1	PIPSL	psi-mi:“MI:2364”(proximity)	0.270
TGOLN2	BLTP3B	psi-mi:“MI:2364”(proximity)	0.270
TGOLN2	TRAPPC13	psi-mi:“MI:2364”(proximity)	0.270
FGFR1	BLTP3B	psi-mi:“MI:2364”(proximity)	0.270
FGFR4	SH3PXD2B	psi-mi:“MI:2364”(proximity)	0.270
TJAP1	KRT75	psi-mi:“MI:0915”(physical association)	0.000

BioGRID (71): TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS), TJAP1 (Affinity Capture-MS)

ESM2 similar proteins: A0A8I3QA39, A1YB07, A2A6T1, A2A9T0, A2AHG0, A5PKL7, A6NKD9, A7MCY6, B8A5S6, D3ZD05, E1BEQ5, E1U8D0, E9Q6B2, F1MRK3, G3V735, O14529, O60299, O75145, O94964, P60469, Q1LZH7, Q3LUD4, Q3UIL6, Q499E4, Q5JTD0, Q5RCR6, Q5XIA0, Q62036, Q63ZY3, Q6DG50, Q6IQ23, Q6NZT2, Q6PDH0, Q86UU1, Q86X02, Q8BX02, Q8C7U1, Q8IY63, Q8K1Q4, Q8K371

Diamond homologs: O88881, Q5JTD0, Q68EF6, Q6R6L0, Q9BUH8, Q9DCD5

SIGNOR signaling

0 interactions.

Enriched among interaction partners

Reactome pathways and GO biological processes over-represented among this gene’s 40 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
Neurexins and neuroligins	6	47.3×	4e-07

GO biological processes:

GO term	Partners	Fold	FDR
chemical synaptic transmission	5	11.7×	5e-03
protein transport	6	8.0×	5e-03

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	1
Likely pathogenic	0
Uncertain significance	81
Likely benign	3
Benign	0

Top pathogenic / likely-pathogenic (1)

Variant ID	HGVS	Classification
1072088	NC_000006.11:g.(?42928506)(43737486_?)del	Pathogenic

SpliceAI

2573 predictions. Top by Δscore:

Variant	Effect	Δscore
6:43477626:A:T	donor_gain	1.0000
6:43497872:T:A	acceptor_gain	1.0000
6:43497873:G:A	acceptor_gain	1.0000
6:43497876:TTCA:T	acceptor_loss	1.0000
6:43497877:TCAG:T	acceptor_loss	1.0000
6:43497879:A:AG	acceptor_gain	1.0000
6:43497879:AGG:A	acceptor_loss	1.0000
6:43497880:G:GT	acceptor_gain	1.0000
6:43497880:GGA:G	acceptor_gain	1.0000
6:43497974:GACG:G	donor_gain	1.0000
6:43497976:CGGTA:C	donor_loss	1.0000
6:43497978:G:GG	donor_gain	1.0000
6:43497978:G:T	donor_loss	1.0000
6:43497979:T:A	donor_loss	1.0000
6:43499097:GGAG:G	donor_gain	1.0000
6:43499098:GAGG:G	donor_gain	1.0000
6:43501516:A:AG	acceptor_gain	1.0000
6:43501517:C:G	acceptor_gain	1.0000
6:43501669:T:G	donor_gain	1.0000
6:43501669:T:TG	donor_gain	1.0000
6:43501673:GGA:G	donor_gain	1.0000
6:43501675:A:AG	donor_gain	1.0000
6:43502348:TGGT:T	donor_loss	1.0000
6:43502350:G:GG	donor_gain	1.0000
6:43503396:TTCAG:T	acceptor_loss	1.0000
6:43503399:A:AG	acceptor_gain	1.0000
6:43503399:AGATC:A	acceptor_loss	1.0000
6:43503400:G:GA	acceptor_gain	1.0000
6:43503400:GA:G	acceptor_gain	1.0000
6:43503400:GAT:G	acceptor_gain	1.0000

AlphaMissense

3619 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
6:43502285:T:C	L98P	0.999
6:43503660:T:C	L178P	0.999
6:43505214:A:C	S345R	0.999
6:43505216:C:A	S345R	0.999
6:43505216:C:G	S345R	0.999
6:43505254:T:A	I358N	0.999
6:43505810:G:C	K543N	0.999
6:43505810:G:T	K543N	0.999
6:43501680:T:C	F95L	0.998
6:43501681:T:C	F95S	0.998
6:43501682:C:A	F95L	0.998
6:43501682:C:G	F95L	0.998
6:43502312:G:C	R107P	0.998
6:43502327:T:C	L112S	0.998
6:43502339:T:C	L116P	0.998
6:43503453:T:C	L147P	0.998
6:43503465:T:C	L151P	0.998
6:43503651:C:A	A175D	0.998
6:43503663:T:C	L179P	0.998
6:43505229:T:C	C350R	0.998
6:43505244:C:A	R355S	0.998
6:43505254:T:C	I358T	0.998
6:43505783:G:C	R534S	0.998
6:43505783:G:T	R534S	0.998
6:43505785:T:C	M535T	0.998
6:43505796:C:G	H539D	0.998
6:43505798:C:A	H539Q	0.998
6:43505798:C:G	H539Q	0.998
6:43505805:C:A	R542S	0.998
6:43501552:T:C	L52P	0.997

dbSNP variants (sampled 300 via entrez): RS1000001073 (6:43502838 T>A), RS1000379983 (6:43479314 C>G,T), RS1000400297 (6:43489710 G>A), RS1000412669 (6:43478987 T>G), RS1000579960 (6:43490871 G>A,C), RS1000598392 (6:43502402 G>A,C), RS1000642051 (6:43503561 G>A,C), RS1000660686 (6:43485539 A>C), RS1000688047 (6:43491208 GGAT>G), RS1000742968 (6:43477484 C>A,T), RS1000919677 (6:43484423 T>C), RS1000933928 (6:43491416 G>A,T), RS1000988503 (6:43490457 C>T), RS1001040955 (6:43484749 G>A), RS1001448673 (6:43503551 G>A)

Disease associations

OMIM: gene MIM:612658 | disease phenotypes:

GenCC curated gene-disease

Mondo (0):

Orphanet (0):

HPO phenotypes

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

GWAS associations

5 associations (top):

Study	Trait	p-value
GCST002279_21	PR interval in Tripanosoma cruzi seropositivity	2.000000e-07
GCST005956_58	Waist-to-hip ratio adjusted for BMI	7.000000e-26
GCST005957_1	Waist-to-hip ratio adjusted for BMI (age <50)	2.000000e-14
GCST005958_2	Waist-to-hip ratio adjusted for BMI (age >50)	2.000000e-19
GCST005962_2	Waist-to-hip ratio adjusted for BMI x sex x age interaction (4df test)	3.000000e-31

EFO canonical traits (4, from GWAS)

EFO ID	Trait name
EFO:0004462	PR interval
EFO:0007788	BMI-adjusted waist-hip ratio
EFO:0008007	age at assessment
EFO:0008343	sex interaction measurement

Drugs & pharmacology

Drug and pharmacology data

Is drug target: no

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

CTD chemical–gene interactions

26 total (human), top 26 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Arsenic	affects expression, affects methylation	2
Benzo(a)pyrene	affects methylation, decreases methylation	2
Valproic Acid	affects expression, decreases methylation	2
aristolochic acid I	increases expression	1
FR900359	affects phosphorylation	1
beta-lapachone	decreases expression	1
sodium arsenite	increases expression	1
perfluorooctanoic acid	increases expression	1
benzo(e)pyrene	decreases methylation	1
aflatoxin B2	decreases methylation	1
di-n-butylphosphoric acid	affects expression	1
perfluorooctane sulfonic acid	increases expression	1
ICG 001	increases expression	1
abrine	increases expression	1
4-(4-((5-(4,5-dimethyl-2-nitrophenyl)-2-furanyl)methylene)-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl)benzoic acid	increases expression	1
Temozolomide	increases expression	1
Vehicle Emissions	decreases expression, increases abundance	1
Caffeine	decreases phosphorylation	1
Doxorubicin	decreases expression	1
Ivermectin	decreases expression	1
Lead	affects expression	1
Methapyrilene	decreases methylation	1
Smoke	decreases expression	1
Aflatoxin B1	decreases methylation	1
Cadmium Chloride	decreases expression	1
Particulate Matter	decreases expression, increases abundance	1

Clinical trials (associated diseases)

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