Seroatlas · Human Serome Atlas

SPAG9

C-Jun-amino-terminal kinase-interacting protein 4

Also known as: CT89, FLJ13450, FLJ14006, FLJ26141, FLJ34602, HLC4, HSS, JIP-4, JIP4, JIP4_HUMAN, JLP, KIAA0516, MGC117291, MGC14967, MGC74461, PHET, PIG6, SYD1

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

Protein identityUniProt · HPA

UniProt accession: O60271
Gene: SPAG9
Ensembl: ENSG00000008294
Chromosome: 17
Canonical length: 1321 aa
Protein class: Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins
Subcellular location: Centriolar satellite,Cytosol
Quaternary structure: Homodimer

OverviewNCBI Gene

This gene encodes a member of the cancer testis antigen gene family. The encoded protein functions as a scaffold protein that structurally organizes mitogen-activated protein kinases and mediates c-Jun-terminal kinase signaling. This protein also binds to kinesin-1 and may be involved in microtubule-based membrane transport. This protein may play a role in tumor growth and development. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Oct 2011]

Canonical amino-acid sequenceUniProt

1321 residues, UniProt reviewed canonical sequence.

>O60271|SPAG9
     1  MELEDGVVYQ EEPGGSGAVM SERVSGLAGS IYREFERLIG RYDEEVVKEL MPLVVAVLEN
    61  LDSVFAQDQE HQVELELLRD DNEQLITQYE REKALRKHAE EKFIEFEDSQ EQEKKDLQTR
   121  VESLESQTRQ LELKAKNYAD QISRLEEREA ELKKEYNALH QRHTEMIHNY MEHLERTKLH
   181  QLSGSDQLES TAHSRIRKER PISLGIFPLP AGDGLLTPDA QKGGETPGSE QWKFQELSQP
   241  RSHTSLKVSN SPEPQKAVEQ EDELSDVSQG GSKATTPAST ANSDVATIPT DTPLKEENEG
   301  FVKVTDAPNK SEISKHIEVQ VAQETRNVST GSAENEEKSE VQAIIESTPE LDMDKDLSGY
   361  KGSSTPTKGI ENKAFDRNTE SLFEELSSAG SGLIGDVDEG ADLLGMGREV ENLILENTQL
   421  LETKNALNIV KNDLIAKVDE LTCEKDVLQG ELEAVKQAKL KLEEKNRELE EELRKARAEA
   481  EDARQKAKDD DDSDIPTAQR KRFTRVEMAR VLMERNQYKE RLMELQEAVR WTEMIRASRE
   541  NPAMQEKKRS SIWQFFSRLF SSSSNTTKKP EPPVNLKYNA PTSHVTPSVK KRSSTLSQLP
   601  GDKSKAFDFL SEETEASLAS RREQKREQYR QVKAHVQKED GRVQAFGWSL PQKYKQVTNG
   661  QGENKMKNLP VPVYLRPLDE KDTSMKLWCA VGVNLSGGKT RDGGSVVGAS VFYKDVAGLD
   721  TEGSKQRSAS QSSLDKLDQE LKEQQKELKN QEELSSLVWI CTSTHSATKV LIIDAVQPGN
   781  ILDSFTVCNS HVLCIASVPG ARETDYPAGE DLSESGQVDK ASLCGSMTSN SSAETDSLLG
   841  GITVVGCSAE GVTGAATSPS TNGASPVMDK PPEMEAENSE VDENVPTAEE ATEATEGNAG
   901  SAEDTVDISQ TGVYTEHVFT DPLGVQIPED LSPVYQSSND SDAYKDQISV LPNEQDLVRE
   961  EAQKMSSLLP TMWLGAQNGC LYVHSSVAQW RKCLHSIKLK DSILSIVHVK GIVLVALADG
  1021  TLAIFHRGVD GQWDLSNYHL LDLGRPHHSI RCMTVVHDKV WCGYRNKIYV VQPKAMKIEK
  1081  SFDAHPRKES QVRQLAWVGD GVWVSIRLDS TLRLYHAHTY QHLQDVDIEP YVSKMLGTGK
  1141  LGFSFVRITA LMVSCNRLWV GTGNGVIISI PLTETNKTSG VPGNRPGSVI RVYGDENSDK
  1201  VTPGTFIPYC SMAHAQLCFH GHRDAVKFFV AVPGQVISPQ SSSSGTDLTG DKAGPSAQEP
  1261  GSQTPLKSML VISGGEGYID FRMGDEGGES ELLGEDLPLE PSVTKAERSH LIVWQVMYGN
  1321  E

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPAG9 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: Other membrane
Secreted: No
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.48
Highest tissue expression: 72 nTPM

Expression across tissuesHPA

Tissue

spinal cord: 72 nTPM
skeletal muscle: 63 nTPM
cerebral cortex: 58 nTPM
midbrain: 52 nTPM
testis: 48 nTPM
amygdala: 44 nTPM

Single-cell type

neutrophils: 2,267 nCPM
endometrial glandular cells: 1,577 nCPM
endometrial luminal cells: 889 nCPM
ocular epithelial cells: 866 nCPM
urothelial cells: 817 nCPM
monocytes: 687 nCPM

Immune cell

neutrophil: 12 nTPM
basophil: 9.2 nTPM
T-reg: 1.7 nTPM
myeloid DC: 1.3 nTPM
classical monocyte: 1.2 nTPM
gdT-cell: 1.2 nTPM

Brain region

white matter: 208 nTPM
medulla oblongata: 147 nTPM
basal ganglia: 144 nTPM
pons: 139 nTPM
cerebellum: 139 nTPM
spinal cord: 137 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SPAG9.

Disease | ImmuneIEDB

Conditions an epitope on SPAG9 was assayed in.

colon adenocarcinoma T cell
chronic myeloid leukemia T cell

ReferencesPubMed · IEDB

Publications for SPAG9 from three distinct lines of evidence, kept separate because they answer different questions: whether antibodies are directed at the protein, whether a B-cell epitope has been mapped on it, and whether a T-cell epitope has. Each is labelled with its source.

Reference: AutoantibodyPubMed

4 publications

Sperm-associated antigen 9, a novel biomarker for early detection of breast cancer.
2009 · Cancer Epidemiol Biomarkers Prev · RCR 1.7 · 70 citations
The expression of DAMP proteins HSP70 and cancer-testis antigen SPAG9 in peripheral blood of patients with HCC and lung cancer.
2017 · Cell Stress Chaperones · RCR 0.7 · 20 citations
Cancer testis antigen SPAG9 is a promising marker for the diagnosis and treatment of lung cancer.
2016 · Oncol Rep · RCR 0.5 · 15 citations
Serum levels of anti-sperm-associated antigen 9 antibody are elevated in patients with hepatocellular carcinoma.
2017 · Oncol Lett · RCR 0.2 · 6 citations

Reference: T cellIEDB

2 publications

Safety and Activity of PolyPEPI1018 Combined with Maintenance Therapy in Metastatic Colorectal Cancer: an Open-Label, Multicenter, Phase Ib Study.
2022 · Clin Cancer Res · RCR 1.7 · 29 citations
Immune Surveillance in Chronic Myeloid Leukemia: Tumor Antigen Expression and CD8+ T Cell Function in the Context of Treatment- Free Remission.
2026 · Arch Immunol Ther Exp (Warsz)

Sources: PubMed — antigen-level antibody evidence from a custom retrieval. Records matching a controlled set of autoantibody terms (the MeSH descriptors Autoantibodies and Autoantigens, with title and abstract term variants) were obtained through NCBI E-utilities, and their titles and abstracts parsed for constructions that direct an antibody at a named protein rather than for co-occurrence. Captured names were resolved against UniProt nomenclature and each antigen adjudicated individually against the source text. IEDB — curated epitope assays from the Immune Epitope Database (Vita et al., Nucleic Acids Research 2019). Bibliographic records from PubMed and MeSH, U.S. National Library of Medicine; citation metrics from NIH iCite (Hutchins et al., PLoS Biology 2016). Titles link to PubMed; abstracts are not reproduced here. The NLM does not endorse this analysis.

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): 0.14
gnomAD pLI: 1
gnomAD missense Z: 3.13
DepMap mean gene effect: -0.25
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 7% 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

InteractionsUniProt · HPA

Protein binding partners of SPAG9 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads SPAG9 as an antibody target. Whether an autoantibody or antibody against SPAG9 could matter depends on whether native SPAG9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPAG9 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 SPAG9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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