A1BG

Summary

A1BG (alpha-1-B glycoprotein, HGNC:5) is a protein-coding gene on chromosome 19q13.43, encoding Alpha-1B-glycoprotein (P04217).

The protein encoded by this gene is a plasma glycoprotein of unknown function. The protein shows sequence similarity to the variable regions of some immunoglobulin supergene family member proteins.

Source: NCBI Gene 1 — RefSeq curated summary.

At a glance

• Clinical variants (ClinVar): 95 total — 5 pathogenic
• MANE Select transcript: NM_130786

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:5
Approved symbol	A1BG
Name	alpha-1-B glycoprotein
Location	19q13.43
Locus type	gene with protein product
Status	Approved
Ensembl gene	ENSG00000121410
Ensembl biotype	protein_coding
OMIM	138670
Entrez	1

Gene structure

Transcript identifiers

Ensembl transcripts: 7 — 5 protein_coding, 1 retained_intron, 1 protein_coding_CDS_not_defined

ENST00000263100, ENST00000595014, ENST00000596924, ENST00000598345, ENST00000600966, ENST00000850949, ENST00000850950

RefSeq mRNA: 1 — MANE Select: NM_130786 NM_130786

CCDS: CCDS12976

Canonical transcript exons

ENST00000263100 — 8 exons

Exon	Start	End
ENSE00001247383	58353404	58353492
ENSE00003494356	58352283	58352555
ENSE00003509215	58351391	58351687
ENSE00003510402	58353292	58353327
ENSE00003598943	58352928	58353197
ENSE00003663075	58350370	58350651
ENSE00003693068	58347353	58347640
ENSE00004282893	58345183	58347029

Expression profiles

Bgee: expression breadth ubiquitous, 136 present calls, max score 99.75.

FANTOM5 (CAGE): breadth ubiquitous, TPM avg 19.4035 / max 3042.2456, expressed in 1646 samples.

FANTOM5 promoters (4 alternative TSS)

Promoter ID	TPM avg	Samples expressed
182951	11.1947	1635
182952	4.1362	14
182950	2.0684	947
182953	2.0042	12

Top tissues by expression

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

Tissue	Anatomy ID	Expression score	Quality
right lobe of liver	UBERON:0001114	99.75	gold quality
liver	UBERON:0002107	99.39	gold quality
adenohypophysis	UBERON:0002196	93.86	gold quality
pituitary gland	UBERON:0000007	93.51	gold quality
C1 segment of cervical spinal cord	UBERON:0006469	93.46	gold quality
endocervix	UBERON:0000458	90.65	gold quality
right coronary artery	UBERON:0001625	90.46	gold quality
putamen	UBERON:0001874	90.34	gold quality
nucleus accumbens	UBERON:0001882	89.79	gold quality
amygdala	UBERON:0001876	89.66	gold quality
temporal lobe	UBERON:0001871	89.65	gold quality
right atrium auricular region	UBERON:0006631	89.58	gold quality
Ammon’s horn	UBERON:0001954	89.20	gold quality
caudate nucleus	UBERON:0001873	88.29	gold quality
granulocyte	CL:0000094	88.11	gold quality
monocyte	CL:0000576	88.02	gold quality
ectocervix	UBERON:0012249	88.02	gold quality
left coronary artery	UBERON:0001626	87.88	gold quality
tibial artery	UBERON:0007610	87.71	gold quality
popliteal artery	UBERON:0002250	87.69	gold quality
leukocyte	CL:0000738	87.68	gold quality
substantia nigra	UBERON:0002038	87.51	gold quality
tibial nerve	UBERON:0001323	87.12	gold quality
prefrontal cortex	UBERON:0000451	86.90	gold quality
spleen	UBERON:0002106	86.70	gold quality
brain	UBERON:0000955	86.42	gold quality
body of uterus	UBERON:0009853	86.18	gold quality
left uterine tube	UBERON:0001303	85.96	gold quality
myometrium	UBERON:0001296	85.95	gold quality
anterior cingulate cortex	UBERON:0009835	85.59	gold quality

Single-cell (SCXA)

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

Experiment	Marker?	Max mean expression
E-MTAB-9801	yes	5.88
E-ANND-3	no	2.52

Regulation

Is transcription factor: no

miRNA regulators (miRDB)

19 targeting A1BG, 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-4510	100.00	66.60	2050
HSA-MIR-6127	100.00	66.76	2188
HSA-MIR-6129	100.00	66.46	2080
HSA-MIR-6130	100.00	66.69	2012
HSA-MIR-6133	100.00	66.48	2064
HSA-MIR-23A-3P	99.95	74.24	3163
HSA-MIR-23B-3P	99.95	74.24	3163
HSA-MIR-23C	99.95	73.92	3192
HSA-MIR-6783-3P	99.89	67.92	2059
HSA-MIR-1343-3P	99.89	66.78	1815
HSA-MIR-6780A-5P	99.88	66.69	2776
HSA-MIR-6515-3P	99.82	68.19	1933
HSA-MIR-5004-5P	99.68	66.63	1294
HSA-MIR-7106-5P	99.53	67.47	3574
HSA-MIR-4292	99.16	65.57	1767
HSA-MIR-6791-5P	99.16	65.92	1844
HSA-MIR-939-3P	98.97	65.07	2347
HSA-MIR-3192-5P	96.98	65.76	1926
HSA-MIR-4707-5P	90.95	65.69	110

Literature-anchored findings (GeneRIF, showing 8)

• there are two distinct steps in the repression of engrailed by Runt (PMID:12145660)
• These proteins provide a paradigm for understanding DNA-binding-independent regulation by developmentally important transcription factors. (PMID:12732185)
• Contrasting responses of different downstream targets to Runt in the presence or absence of Ftz is thus central to the combinatorial logic of the pair-rule to segment-polarity transition. (PMID:15102703)
• Lilli plays an architectural role in facilitating transcriptional activation that depends both on the target gene and the developmental context (PMID:17137570)
• Runt-dependent regulation in the Drosophila blastoderm embryo relies on unique, target-gene-specific molecular interactions. (PMID:21325629)
• A dual role for DNA binding by Runt in activation and repression of sloppy paired transcription. (PMID:34432496)
• ABerrant Chloroplast development gene ABC4 was confirmed to be At1g60600. (PMID:15686525)
• Data show the X-ray crystal structure models of the full-length portal. (PMID:21439834)

Cross-species orthologs

3 orthologs

Organism	Symbol	Gene ID
mus_musculus	A1bg	ENSMUSG00000022347
rattus_norvegicus	A1bg	ENSRNOG00000004692
rattus_norvegicus	A1bgl1	ENSRNOG00000037549

Paralogs (25): GP6 (ENSG00000088053), LILRB1 (ENSG00000104972), LILRA1 (ENSG00000104974), LILRB5 (ENSG00000105609), KIR2DL1 (ENSG00000125498), LILRB2 (ENSG00000131042), IGSF1 (ENSG00000147255), LAIR2 (ENSG00000167618), KIR3DL1 (ENSG00000167633), OSCAR (ENSG00000170909), FCAR (ENSG00000186431), LILRB4 (ENSG00000186818), LILRA5 (ENSG00000187116), KIR2DL4 (ENSG00000189013), VSTM1 (ENSG00000189068), NCR1 (ENSG00000189430), LILRB3 (ENSG00000204577), KIR2DS4 (ENSG00000221957), LILRA4 (ENSG00000239961), LILRA2 (ENSG00000239998), KIR3DL2 (ENSG00000240403), KIR3DL3 (ENSG00000242019), KIR2DL3 (ENSG00000243772), LILRA6 (ENSG00000244482), TARM1 (ENSG00000248385)

Protein

Protein identifiers

Alpha-1B-glycoprotein — P04217 (reviewed: P04217)

Alternative names: Alpha-1-B glycoprotein

All UniProt accessions (3): P04217, M0R009, V9HWD8

UniProt curated annotations — full annotation on UniProt →

Subunit / interactions. Interacts with CRISP3.

Subcellular location. Secreted.

Tissue specificity. Plasma.

Isoforms (2)

UniProt ID	Names	Canonical?
P04217-1	1	yes
P04217-2	2

RefSeq proteins (1): NP_570602* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR003598	Ig_sub2	Domain
IPR003599	Ig_sub	Domain
IPR007110	Ig-like_dom	Domain
IPR013783	Ig-like_fold	Homologous_superfamily
IPR016332	A1B_glyco/leuk_Ig-like_rcpt	Family
IPR036179	Ig-like_dom_sf	Homologous_superfamily
IPR050412	Ig-like_Receptors_ImmuneReg	Family

Pfam: PF13895

UniProt features (25 total): sequence conflict 6, disulfide bond 5, domain 5, glycosylation site 4, sequence variant 2, signal peptide 1, chain 1, splice variant 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-P04217-F1	86.63	0.63

Functional residue map

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

Disulfide bonds (5): 49–93, 139–182, 232–279, 325–374, 423–470

Glycosylation sites (4): 371, 44, 179, 363

Function

Pathways and Gene Ontology

Reactome pathways

7 pathways

ID	Pathway
R-HSA-114608	Platelet degranulation
R-HSA-6798695	Neutrophil degranulation
R-HSA-109582	Hemostasis
R-HSA-168249	Innate Immune System
R-HSA-168256	Immune System
R-HSA-76002	Platelet activation, signaling and aggregation
R-HSA-76005	Response to elevated platelet cytosolic Ca2+

MSigDB gene sets: 90 (showing top): GOBP_RESPONSE_TO_NITROGEN_COMPOUND, REACTOME_INNATE_IMMUNE_SYSTEM, GOCC_SECRETORY_GRANULE, REACTOME_PLATELET_ACTIVATION_SIGNALING_AND_AGGREGATION, CERVERA_SDHB_TARGETS_1_DN, GOBP_CELLULAR_RESPONSE_TO_OXYGEN_CONTAINING_COMPOUND, GOBP_CELLULAR_RESPONSE_TO_HORMONE_STIMULUS, GOBP_RESPONSE_TO_GROWTH_HORMONE, GOBP_RESPONSE_TO_OXYGEN_CONTAINING_COMPOUND, GOBP_CELLULAR_RESPONSE_TO_NITROGEN_COMPOUND, GOBP_RESPONSE_TO_HORMONE, GOCC_PLATELET_ALPHA_GRANULE, GOCC_SECRETORY_VESICLE, GOCC_VESICLE_LUMEN, GOCC_BLOOD_MICROPARTICLE

GO Biological Process (1): immune response-regulating signaling pathway (GO:0002764)

GO Molecular Function (0):

GO Cellular Component (8): extracellular region (GO:0005576), obsolete extracellular space (GO:0005615), plasma membrane (GO:0005886), platelet alpha granule lumen (GO:0031093), secretory granule lumen (GO:0034774), extracellular exosome (GO:0070062), blood microparticle (GO:0072562), ficolin-1-rich granule lumen (GO:1904813)

Reactome top-level categories

Rollup of top-5 pathways:

Category	Pathways
Response to elevated platelet cytosolic Ca2+	1
Innate Immune System	1
Immune System	1
Hemostasis	1
Platelet activation, signaling and aggregation	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
cellular anatomical structure	2
signal transduction	1
regulation of immune response	1
membrane	1
cell periphery	1
platelet alpha granule	1
secretory granule lumen	1
secretory granule	1
cytoplasmic vesicle lumen	1
extracellular vesicle	1
extracellular region	1
intracellular organelle lumen	1
ficolin-1-rich granule	1

Protein interactions and networks

STRING

1034 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
A1BG	GRB2	P29354	992
A1BG	PTPN11	Q06124	939
A1BG	CRISP3	P54108	920
A1BG	GAB2	Q9UQC2	856
A1BG	GAB3	Q8WWW8	821
A1BG	CRK	P46108	746
A1BG	AHSG	P02765	736
A1BG	A2M	P01023	692
A1BG	TF	P02787	642
A1BG	SHC1	P29353	607
A1BG	ALB	P02768	604
A1BG	GC	P02774	603
A1BG	FGB	P02675	599
A1BG	AMBP	P00977	596
A1BG	ORM1	P02763	592

IntAct

24 interactions, top by confidence:

A	B	Type	Score
	CD5L	psi-mi:“MI:0915”(physical association)	0.400
	LECT2	psi-mi:“MI:0915”(physical association)	0.400
A1BG	ABCC6	psi-mi:“MI:0915”(physical association)	0.370
PRDX4	A1BG	psi-mi:“MI:0915”(physical association)	0.370
A1BG	SETD7	psi-mi:“MI:0915”(physical association)	0.370
A1BG	ANXA7	psi-mi:“MI:0915”(physical association)	0.370
CDKN1A	A1BG	psi-mi:“MI:0915”(physical association)	0.370
GRB7	A1BG	psi-mi:“MI:0915”(physical association)	0.370
SMN1	A1BG	psi-mi:“MI:0915”(physical association)	0.370
A1BG	SNCA	psi-mi:“MI:0915”(physical association)	0.370
TK1	A1BG	psi-mi:“MI:0915”(physical association)	0.370
MAPT	SHTN1	psi-mi:“MI:0914”(association)	0.350
A1BG	WDR62	psi-mi:“MI:0914”(association)	0.350
GDPD1	CP	psi-mi:“MI:0914”(association)	0.350
PHF11	A2ML1	psi-mi:“MI:0914”(association)	0.350
RHBDD1	A2ML1	psi-mi:“MI:0914”(association)	0.350
MATN2	IGLL5	psi-mi:“MI:0914”(association)	0.350
UBE2U	IGLL5	psi-mi:“MI:0914”(association)	0.350
KLK10	IGLL5	psi-mi:“MI:0914”(association)	0.350
A1BG	UBR4	psi-mi:“MI:0914”(association)	0.350
		psi-mi:“MI:0914”(association)	0.350

BioGRID (49): A1BG (Affinity Capture-RNA), A1BG (Affinity Capture-MS), A1BG (Synthetic Growth Defect), A1BG (Affinity Capture-MS), ZBTB40 (Affinity Capture-MS), PSME4 (Affinity Capture-MS), UBAC1 (Affinity Capture-MS), WDR62 (Affinity Capture-MS), KCMF1 (Affinity Capture-MS), RNF123 (Affinity Capture-MS), UBR4 (Affinity Capture-MS), UBXN1 (Affinity Capture-MS), FDXR (Affinity Capture-MS), A1BG (Affinity Capture-MS), A1BG (Affinity Capture-MS)

ESM2 similar proteins: A6NMB1, A7LCJ3, G1T7E7, G1TR84, M3XWH1, O15389, O43699, O70540, P04217, P05362, P0DP72, P13597, P20138, P32942, P33729, Q00238, Q08ET2, Q14773, Q28125, Q28730, Q28806, Q2KJF1, Q5NKT8, Q5NKU6, Q5NKV4, Q5NKV6, Q5NKV9, Q60625, Q62230, Q64JA4, Q6DN72, Q7L513, Q80ZE3, Q91Y57, Q920A9, Q920G3, Q92154, Q95132, Q95LH0, Q96A28

Diamond homologs: B6A8C7, B6A8R8, O75022, O75023, P04217, P0C191, P24071, P43628, P43629, P43630, P59901, P83555, P97484, Q14943, Q2KJF1, Q6GTX8, Q6ISS4, Q6PI73, Q6UX27, Q7TQA1, Q8IYS5, Q8MJZ2, Q8MJZ7, Q8N109, Q8N149, Q8N423, Q8N6C5, Q8N6C8, Q8N743, Q8NHJ6, Q8NHK3, Q8NHL6, Q8VBT3, Q925N6, Q9H7L2, Q9HCN6, P39092, P82957, Q19LI2, Q9EPH1

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

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

Classification	Count (floor)
Pathogenic	5
Likely pathogenic	0
Uncertain significance	82
Likely benign	2
Benign	0

Top pathogenic / likely-pathogenic (5)

Variant ID	HGVS	Classification
153721	GRCh38/hg38 19q13.41-13.43(chr19:52143873-58445521)x3	Pathogenic
394342	GRCh37/hg19 19q13.33-13.43(chr19:50489390-59095359)x3	Pathogenic
443498	GRCh37/hg19 19p13.3-q13.43(chr19:260912-58956888)x3	Pathogenic
59126	GRCh38/hg38 19q13.33-13.43(chr19:49907832-58557889)x3	Pathogenic
59128	GRCh38/hg38 19q13.43(chr19:56363208-58581203)x3	Pathogenic

SpliceAI

1329 predictions. Top by Δscore:

Variant	Effect	Δscore
19:58352330:T:TA	donor_gain	1.0000
19:58352331:C:A	donor_gain	1.0000
19:58352926:A:AC	donor_gain	1.0000
19:58352927:C:CC	donor_gain	1.0000
19:58352958:G:C	donor_gain	1.0000
19:58352968:T:TA	donor_gain	1.0000
19:58350364:GCTCA:G	donor_loss	0.9900
19:58350365:CTCAC:C	donor_loss	0.9900
19:58350366:TCA:T	donor_loss	0.9900
19:58350367:CA:C	donor_loss	0.9900
19:58350369:C:CT	donor_loss	0.9900
19:58351385:GCTCA:G	donor_loss	0.9900
19:58351386:CTCA:C	donor_loss	0.9900
19:58351387:TCACC:T	donor_loss	0.9900
19:58351388:CA:C	donor_loss	0.9900
19:58351390:C:CT	donor_loss	0.9900
19:58351390:CCAT:C	donor_gain	0.9900
19:58351684:GCAG:G	acceptor_gain	0.9900
19:58351685:CAG:C	acceptor_gain	0.9900
19:58351685:CAGC:C	acceptor_gain	0.9900
19:58351686:AG:A	acceptor_gain	0.9900
19:58351687:GCT:G	acceptor_loss	0.9900
19:58351688:C:CC	acceptor_gain	0.9900
19:58351688:CTGC:C	acceptor_loss	0.9900
19:58351689:T:A	acceptor_loss	0.9900
19:58352272:C:A	donor_gain	0.9900
19:58352282:CCGAG:C	donor_gain	0.9900
19:58352285:AGCT:A	donor_gain	0.9900
19:58352286:G:C	donor_gain	0.9900
19:58352927:CTTGG:C	donor_gain	0.9900

AlphaMissense

3170 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
19:58347424:C:G	C470S	0.990
19:58347425:A:T	C470S	0.990
19:58350486:A:C	F359C	0.989
19:58350441:C:G	C374S	0.987
19:58350442:A:T	C374S	0.987
19:58350588:C:G	C325S	0.987
19:58350589:A:T	C325S	0.987
19:58347378:G:C	S485R	0.986
19:58347378:G:T	S485R	0.986
19:58347380:T:G	S485R	0.986
19:58347565:C:G	C423S	0.986
19:58347566:A:T	C423S	0.986
19:58351606:C:G	C232S	0.986
19:58351607:A:T	C232S	0.986
19:58350560:G:C	F334L	0.985
19:58350560:G:T	F334L	0.985
19:58350562:A:G	F334L	0.985
19:58350441:C:T	C374Y	0.984
19:58350561:A:C	F334C	0.982
19:58351578:G:C	F241L	0.982
19:58351578:G:T	F241L	0.982
19:58351580:A:G	F241L	0.982
19:58351606:C:T	C232Y	0.982
19:58350436:A:C	Y376D	0.981
19:58347425:A:G	C470R	0.980
19:58351465:C:G	C279S	0.979
19:58351466:A:T	C279S	0.979
19:58352990:C:G	C93S	0.979
19:58352991:A:T	C93S	0.979
19:58351607:A:G	C232R	0.978

dbSNP variants (sampled 300 via entrez): RS1000277711 (19:58351766 G>A,T), RS1001003416 (19:58347235 C>A,T), RS1001109916 (19:58347463 A>C), RS1001334782 (19:58353284 G>C), RS1001651855 (19:58350697 C>A,T), RS1001660286 (19:58347934 T>C), RS1001775652 (19:58347706 G>A,C,T), RS1003004716 (19:58346854 T>A,G), RS1003820585 (19:58354663 C>T), RS1003887440 (19:58346290 T>C), RS1003900819 (19:58346220 G>A,C), RS1003942142 (19:58351733 C>T), RS1004001857 (19:58346545 G>A), RS1004259425 (19:58352636 A>C,G), RS1004856119 (19:58353648 T>C,G)

Disease associations

OMIM: gene MIM:138670 | 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

33 total (human), top 30 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Valproic Acid	increases expression, increases methylation, affects expression, decreases expression	3
mercuric bromide	decreases expression, affects cotreatment	2
Phenylmercuric Acetate	affects cotreatment, decreases expression	2
Cyclosporine	decreases expression, increases expression	2
Aflatoxin B1	decreases expression	2
dicrotophos	decreases expression	1
propionaldehyde	increases expression	1
bisphenol A	increases expression	1
butyraldehyde	increases expression	1
benazol P	affects expression	1
pentanal	increases expression	1
entinostat	increases expression	1
4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide	affects cotreatment, decreases expression	1
dorsomorphin	decreases expression, affects cotreatment	1
bisphenol S	increases expression	1
jinfukang	increases expression	1
Olanzapine	affects phosphorylation	1
Sunitinib	increases expression	1
Aldehydes	increases expression	1
Cadmium	affects binding	1
Copper	affects binding	1
Fluorides	increases expression	1
Mercury	affects expression	1
Nickel	affects binding	1
Niclosamide	increases expression	1
Quercetin	increases expression	1
Smoke	decreases expression	1
Tetrachlorodibenzodioxin	affects expression	1
Tretinoin	decreases expression	1
Zinc	affects binding	1

Clinical trials (associated diseases)

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