Seroatlas · Human Serome Atlas

SIPA1

Signal-induced proliferation-associated protein 1

Also known as: SIPA1_HUMAN, SPA1

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

Protein identityUniProt · HPA

UniProt accession: Q96FS4
Gene: SIPA1
Ensembl: ENSG00000213445
Chromosome: 11
Canonical length: 1042 aa
Protein class: Predicted intracellular proteins
Subcellular location: Nucleoplasm,Nucleoli,Golgi apparatus,Plasma membrane

OverviewNCBI Gene

The product of this gene is a mitogen induced GTPase activating protein (GAP). It exhibits a specific GAP activity for Ras-related regulatory proteins Rap1 and Rap2, but not for Ran or other small GTPases. This protein may also hamper mitogen-induced cell cycle progression when abnormally or prematurely expressed. It is localized to the perinuclear region. Two alternatively spliced variants encoding the same isoform have been characterized to date. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

1042 residues, UniProt reviewed canonical sequence.

>Q96FS4|SIPA1
     1  MPMWAGGVGS PRRGMAPAST DDLFARKLRQ PARPPLTPHT FEPRPVRGPL LRSGSDAGEA
    61  RPPTPASPRA RAHSHEEASR PAATSTRLFT DPLALLGLPA EEPEPAFPPV LEPRWFAHYD
   121  VQSLLFDWAP RSQGMGSHSE ASSGTLASAE DQAASSDLLH GAPGFVCELG GEGELGLGGP
   181  ASPPVPPALP NAAVSILEEP QNRTSAYSLE HADLGAGYYR KYFYGKEHQN FFGMDESLGP
   241  VAVSLRREEK EGSGGGTLHS YRVIVRTTQL RTLRGTISED ALPPGPPRGL SPRKLLEHVA
   301  PQLSPSCLRL GSASPKVPRT LLTLDEQVLS FQRKVGILYC RAGQGSEEEM YNNQEAGPAF
   361  MQFLTLLGDV VRLKGFESYR AQLDTKTDST GTHSLYTTYQ DHEIMFHVST MLPYTPNNQQ
   421  QLLRKRHIGN DIVTIVFQEP GSKPFCPTTI RSHFQHVFLV VRAHTPCTPH TTYRVAVSRT
   481  QDTPAFGPAL PAGGGPFAAN ADFRAFLLAK ALNGEQAAGH ARQFHAMATR TRQQYLQDLA
   541  TNEVTTTSLD SASRFGLPSL GGRRRAAPRG PGAELQAAGS LVWGVRAAPG ARVAAGAQAS
   601  GPEGIEVPCL LGISAEALVL VAPRDGRVVF NCACRDVLAW TFSEQQLDLY HGRGEAITLR
   661  FDGSPGQAVG EVVARLQLVS RGCETRELAL PRDGQGRLGF EVDAEGFVTH VERFTFAETA
   721  GLRPGARLLR VCGQTLPSLR PEAAAQLLRS APKVCVTVLP PDESGRPRRS FSELYTLSLQ
   781  EPSRRGAPDP VQDEVQGVTL LPTTKQLLHL CLQDGGSPPG PGDLAEERTE FLHSQNSLSP
   841  RSSLSDEAPV LPNTTPDLLL ATTAKPSVPS ADSETPLTQD RPGSPSGSED KGNPAPELRA
   901  SFLPRTLSLR NSISRIMSEA GSGTLEDEWQ AISEIASTCN TILESLSREG QPIPESGDPK
   961  GTPKSDAEPE PGNLSEKVSH LESMLRKLQE DLQKEKADRA ALEEEVRSLR HNNRRLQAES
  1021  ESAATRLLLA SKQLGSPTAD LA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SIPA1 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): 0.4
Highest tissue expression: 90 nTPM

Expression across tissuesHPA

Tissue

spleen: 90 nTPM
lymph node: 57 nTPM
bone marrow: 51 nTPM
appendix: 46 nTPM
small intestine: 35 nTPM
lung: 35 nTPM

Single-cell type

neutrophils: 161 nCPM
esophageal apical cells: 94 nCPM
neutrophil progenitors: 88 nCPM
nk-cells: 84 nCPM
breast lactating cells: 81 nCPM
hofbauer cells: 67 nCPM

Immune cell

neutrophil: 11 nTPM
eosinophil: 9.3 nTPM
gdT-cell: 5.8 nTPM
non-classical monocyte: 4.8 nTPM
naive B-cell: 4.7 nTPM
NK-cell: 4.7 nTPM

Brain region

thalamus: 63 nTPM
medulla oblongata: 56 nTPM
white matter: 52 nTPM
pons: 51 nTPM
spinal cord: 51 nTPM
cerebral cortex: 51 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SIPA1.

Disease | ImmuneIEDB

Conditions an epitope on SIPA1 was assayed in.

narcolepsy B cell
multiple sclerosis B cell
peripheral nervous system disease B cell

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): 0.51
gnomAD pLI: 0
gnomAD missense Z: 2.46
DepMap mean gene effect: -0.08
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

GTPase activator activity

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SIPA1 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

RRP1B

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SIPA1 as an antibody target. Whether an autoantibody or antibody against SIPA1 could matter depends on whether native SIPA1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SIPA1 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 SIPA1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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