Seroatlas · Human Serome Atlas

SIAH3

Seven in absentia homolog 3

Also known as: FLJ39203, SIAH3_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: Q8IW03
Gene: SIAH3
Ensembl: ENSG00000215475
Chromosome: 13
Canonical length: 269 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Mitochondria

OverviewNCBI Gene

Predicted to enable ubiquitin conjugating enzyme binding activity and ubiquitin protein ligase activity. Involved in negative regulation of protein targeting to mitochondrion and regulation of protein stability. Located in mitochondrion and nucleoplasm. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

269 residues, UniProt reviewed canonical sequence.

>Q8IW03|SIAH3
     1  MLFFTQCFGA VLDLIHLRFQ HYKAKRVFSA AGQLVCVVNP THNLKYVSSR RAVTQSAPEQ
    61  GSFHPHHLSH HHCHHRHHHH LRHHAHPHHL HHQEAGLHAN PVTPCLCMCP LFSCQWEGRL
   121  EVVVPHLRQI HRVDILQGAE IVFLATDMHL PAPADWIIMH SCLGHHFLLV LRKQERHEGH
   181  PQFFATMMLI GTPTQADCFT YRLELNRNHR RLKWEATPRS VLECVDSVIT DGDCLVLNTS
   241  LAQLFSDNGS LAIGIAITAT EVLPSEAEM

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SIAH3 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Intracellular
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.41
Highest tissue expression: 2.9 nTPM

Expression across tissuesHPA

Tissue

fallopian tube: 2.9 nTPM
cerebellum: 1.8 nTPM
midbrain: 1.2 nTPM
cerebral cortex: 1.1 nTPM
retina: 1.1 nTPM
basal ganglia: 0.9 nTPM

Single-cell type

endometrial ciliated cells: 72 nCPM
fallopian tube ciliated cells: 50 nCPM
loop of henle epithelial cells: 40 nCPM
brain inhibitory neurons: 40 nCPM
other brain neurons: 32 nCPM
retinal amacrine cells: 31 nCPM

Immune cell

naive CD4 T-cell: 0.1 nTPM
basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM

Brain region

midbrain: 8.7 nTPM
cerebellum: 7.2 nTPM
cerebral cortex: 4.3 nTPM
pons: 4.1 nTPM
hypothalamus: 3.8 nTPM
basal ganglia: 3.7 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 1.59
gnomAD pLI: 0
gnomAD missense Z: -0.35
DepMap mean gene effect: -0.04
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SIAH3 as an antibody target. Whether an autoantibody or antibody against SIAH3 could matter depends on whether native SIAH3 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SIAH3 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label SIAH3 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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