Seroatlas · Human Serome Atlas

SPPL2B

Signal peptide peptidase-like 2B

Also known as: IMP4, KIAA1532, PSL1, SPP2B_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q8TCT7
Gene: SPPL2B
Ensembl: ENSG00000005206
Chromosome: 19
Canonical length: 592 aa
Protein class: Enzymes, Predicted membrane proteins
Subcellular location: Nucleoplasm,Plasma membrane,Centrosome
Quaternary structure: Homodimer

OverviewNCBI Gene

This gene encodes a member of the GXGD family of aspartic proteases. The GXGD proteases are transmembrane proteins with two conserved catalytic motifs localized within the membrane-spanning regions. This enzyme localizes to endosomes, lysosomes, and the plasma membrane. It cleaves the transmembrane domain of tumor necrosis factor alpha to release the intracellular domain, which triggers cytokine expression in the innate and adaptive immunity pathways. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

592 residues, UniProt reviewed canonical sequence.

>Q8TCT7|SPPL2B
     1  MAAAVAAALA RLLAAFLLLA AQVACEYGMV HVVSQAGGPE GKDYCILYNP QWAHLPHDLS
    61  KASFLQLRNW TASLLCSAAD LPARGFSNQI PLVARGNCTF YEKVRLAQGS GARGLLIVSR
   121  ERLVPPGGNK TQYDEIGIPV ALLSYKDMLD IFTRFGRTVR AALYAPKEPV LDYNMVIIFI
   181  MAVGTVAIGG YWAGSRDVKK RYMKHKRDDG PEKQEDEAVD VTPVMTCVFV VMCCSMLVLL
   241  YYFYDLLVYV VIGIFCLASA TGLYSCLAPC VRRLPFGKCR IPNNSLPYFH KRPQARMLLL
   301  ALFCVAVSVV WGVFRNEDQW AWVLQDALGI AFCLYMLKTI RLPTFKACTL LLLVLFLYDI
   361  FFVFITPFLT KSGSSIMVEV ATGPSDSATR EKLPMVLKVP RLNSSPLALC DRPFSLLGFG
   421  DILVPGLLVA YCHRFDIQVQ SSRVYFVACT IAYGVGLLVT FVALALMQRG QPALLYLVPC
   481  TLVTSCAVAL WRRELGVFWT GSGFAKVLPP SPWAPAPADG PQPPKDSATP LSPQPPSEEP
   541  ATSPWPAEQS PKSRTSEEMG AGAPMREPGS PAESEGRDQA QPSPVTQPGA SA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SPPL2B 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: Cell surface
Secreted: No
Transmembrane segments: 9
Mean surface accessibility (rSASA): 0.35
Highest tissue expression: 61 nTPM

Expression across tissuesHPA

Tissue

testis: 61 nTPM
pituitary gland: 59 nTPM
cerebellum: 50 nTPM
small intestine: 49 nTPM
pancreas: 46 nTPM
colon: 40 nTPM

Single-cell type

late spermatids: 168 nCPM
late primary spermatocytes: 111 nCPM
astrocytes: 100 nCPM
foveolar cells: 88 nCPM
tuft cells: 81 nCPM
ependymal cells: 79 nCPM

Immune cell

plasmacytoid DC: 17 nTPM
naive B-cell: 13 nTPM
basophil: 12 nTPM
myeloid DC: 9.4 nTPM
memory B-cell: 8.2 nTPM
classical monocyte: 7.7 nTPM

Brain region

medulla oblongata: 44 nTPM
choroid plexus: 41 nTPM
white matter: 37 nTPM
pons: 37 nTPM
midbrain: 37 nTPM
cerebellum: 36 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): 0.95
gnomAD pLI: 0
DepMap mean gene effect: -0.98
DepMap dependency class: common

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 5% 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 SPPL2B 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 SPPL2B as an antibody target. Whether an autoantibody or antibody against SPPL2B could matter depends on whether native SPPL2B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SPPL2B is annotated at the cell surface, where native SPPL2B is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label SPPL2B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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