SPN

Protein identityUniProt · HPA

UniProt accession

P16150

Gene

SPN

Ensembl

ENSG00000197471

Chromosome

16

Canonical length

400 aa

Protein class

CD markers, Predicted membrane proteins

Subcellular location

Plasma membrane

OverviewNCBI Gene

This gene encodes a highly sialylated glycoprotein that functions in antigen-specific activation of T cells, and is found on the surface of thymocytes, T lymphocytes, monocytes, granulocytes, and some B lymphocytes. It contains a mucin-like extracellular domain, a transmembrane region and a carboxy-terminal intracellular region. The extracellular domain has a high proportion of serine and threonine residues, allowing extensive O-glycosylation, and has one potential N-glycosylation site, while the carboxy-terminal region has potential phosphorylation sites that may mediate transduction of activation signals. Different glycoforms of this protein have been described. In stimulated immune cells, proteolytic cleavage of the extracellular domain occurs in some cell types, releasing a soluble extracellular fragment. Defects in expression of this gene are associated with Wiskott-Aldrich syndrome. [provided by RefSeq, Sep 2017]

Canonical amino-acid sequenceUniProt

400 residues, UniProt reviewed canonical sequence.

>P16150|SPN
     1  MATLLLLLGV LVVSPDALGS TTAVQTPTSG EPLVSTSEPL SSKMYTTSIT SDPKADSTGD
    61  QTSALPPSTS INEGSPLWTS IGASTGSPLP EPTTYQEVSI KMSSVPQETP HATSHPAVPI
   121  TANSLGSHTV TGGTITTNSP ETSSRTSGAP VTTAASSLET SRGTSGPPLT MATVSLETSK
   181  GTSGPPVTMA TDSLETSTGT TGPPVTMTTG SLEPSSGASG PQVSSVKLST MMSPTTSTNA
   241  STVPFRNPDE NSRGMLPVAV LVALLAVIVL VALLLLWRRR QKRRTGALVL SRGGKRNGVV
   301  DAWAGPAQVP EEGAVTVTVG GSGGDKGSGF PDGEGSSRRP TLTTFFGRRK SRQGSLAMEE
   361  LKSGSGPSLK GEEEPLVASE DGAVDAPAPD EPEGGDGAAP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPN 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

1

Mean surface accessibility (rSASA)

0.71

Highest tissue expression

68 nTPM

Expression across tissuesHPA

ReferencesPubMed · IEDB

Publications for SPN 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.

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. 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)

1.94

gnomAD pLI

0.01

gnomAD missense Z

-0.09

DepMap mean gene effect

-0.03

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

• apoptotic signaling pathway
• cell surface receptor signaling pathway
• cellular defense response
• chemotaxis
• defense response to bacterium
• establishment or maintenance of cell polarity
• immune response
• leukocyte tethering or rolling
• negative regulation of cell adhesion
• negative regulation of T cell proliferation
• negative regulation of type IV hypersensitivity
• negative thymic T cell selection
• positive regulation of T cell migration
• positive regulation of T cell proliferation
• positive regulation of tumor necrosis factor production
• regulation of defense response to virus
• regulation of immune response
• regulation of T cell migration
• response to protozoan
• signal transduction
• T cell costimulation
• T cell proliferation
• T-helper 1 cell lineage commitment

Molecular functions

• heat shock protein binding
• Hsp70 protein binding
• transmembrane signaling receptor activity

Cellular components

• basement membrane
• cell surface
• external side of plasma membrane
• extracellular exosome
• extracellular space
• membrane
• microvillus
• plasma membrane
• PML body
• uropod

Protein domainsUniProt · Pfam · InterPro

• Leukosialin

KeywordsUniProt

• Cell projection
• Glycoprotein
• Membrane
• Nucleus
• Phosphoprotein
• Signal
• Transmembrane
• Transmembrane helix
• Ubl conjugation

InteractionsUniProt · HPA

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

• CTNNB1
• RDX
• SIGLEC1
• LGALS1