Seroatlas · Human Serome Atlas

GTPBP8

GTP-binding protein 8

Also known as: GTPB8_HUMAN, HSPC135

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

Protein identityUniProt · HPA

UniProt accession: Q8N3Z3
Gene: GTPBP8
Ensembl: ENSG00000163607
Chromosome: 3
Canonical length: 284 aa
Protein class: Predicted intracellular proteins
Subcellular location: Mitochondria

OverviewNCBI Gene

Predicted to enable GTP binding activity; GTPase activity; and metal ion binding activity. Located in mitochondrion. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

284 residues, UniProt reviewed canonical sequence.

>Q8N3Z3|GTPBP8
     1  MAAPGLRLGA GRLFEMPAVL ERLSRYNSTS QAFAEVLRLP KQQLRKLLYP LQEVERFLAP
    61  YGRQDLHLRI FDPSPEDIAR ADNIFTATER NRIDYVSSAV RIDHAPDLPR PEVCFIGRSN
   121  VGKSSLIKAL FSLAPEVEVR VSKKPGHTKK MNFFKVGKHF TVVDMPGYGF RAPEDFVDMV
   181  ETYLKERRNL KRTFLLVDSV VGIQKTDNIA IEMCEEFALP YVIVLTKIDK SSKGHLLKQV
   241  LQIQKFVNMK TQGCFPQLFP VSAVTFSGIH LLRCFIASVT GSLD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against GTPBP8 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): 0.28
Highest tissue expression: 18 nTPM

Expression across tissuesHPA

Tissue

skeletal muscle: 18 nTPM
tongue: 17 nTPM
testis: 14 nTPM
heart muscle: 11 nTPM
lymph node: 11 nTPM
thyroid gland: 9.5 nTPM

Single-cell type

late primary spermatocytes: 151 nCPM
cardiomyocytes: 141 nCPM
epicardial cells: 93 nCPM
early spermatids: 73 nCPM
conjunctival goblet cells: 57 nCPM
salivary duct cells: 51 nCPM

Immune cell

naive CD4 T-cell: 9.5 nTPM
NK-cell: 8.3 nTPM
myeloid DC: 7.9 nTPM
basophil: 7.8 nTPM
memory CD4 T-cell: 7.4 nTPM
naive CD8 T-cell: 6.4 nTPM

Brain region

white matter: 11 nTPM
cerebellum: 8.1 nTPM
choroid plexus: 7.9 nTPM
medulla oblongata: 7.4 nTPM
spinal cord: 7.4 nTPM
cerebral cortex: 7.3 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): 1.51
gnomAD pLI: 0
gnomAD missense Z: -0.56
DepMap mean gene effect: -0.26
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 8% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Molecular functions

Cellular components

mitochondrion

Protein domainsUniProt · Pfam · InterPro

GTP binding domain
P-loop containing nucleoside triphosphate hydrolase
50S ribosome-binding GTPase
GTP-binding protein, ribosome biogenesis, YsxC
EngB-type guanine nucleotide-binding (G) domain
EngB GTPase

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads GTPBP8 as an antibody target. Whether an autoantibody or antibody against GTPBP8 could matter depends on whether native GTPBP8 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

GTPBP8 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 GTPBP8 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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