Seroatlas · Human Serome Atlas

SIRPD

Signal-regulatory protein delta

Also known as: dJ576H24.4, PTPNS1L2, SIRPD_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q9H106
Gene: SIRPD
Ensembl: ENSG00000125900
Chromosome: 20
Canonical length: 197 aa
Protein class: Predicted intracellular proteins, Predicted secreted proteins
Secretome location: Secreted in male reproductive system

OverviewNCBI Gene

Predicted to be located in extracellular region. Predicted to be active in plasma membrane. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

197 residues, UniProt reviewed canonical sequence.

>Q9H106|SIRPD
     1  MPIPASPLHP PLPSLLLYLL LELAGVTHVF HVQQTEMSQT VSTGESIILS CSVPNTLPNG
    61  PVLWFKGTGP NRKLIYNFKQ GNFPRVKEIG DTTKPGNTDF STRIREISLA DAGTYYCVKF
   121  IKGRAIKEYQ SGRGTQVFVT EQNPRPPKNR PAGRAGSRAH HDAHTCLSAL PERNSTNYFV
   181  QPCCCLRLLG LTGLLSK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SIRPD 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: Secreted
Secreted: Yes
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.46
Highest tissue expression: 65 nTPM

Expression across tissuesHPA

Tissue

testis: 65 nTPM
appendix: 2.6 nTPM
bone marrow: 2.6 nTPM
lung: 1.8 nTPM
spleen: 1.4 nTPM
lymph node: 1 nTPM

Single-cell type

late spermatids: 521 nCPM
early spermatids: 429 nCPM
late primary spermatocytes: 86 nCPM
monocyte progenitors: 3.2 nCPM
monocytes: 2.6 nCPM
neutrophils: 1.2 nCPM

Immune cell

neutrophil: 37 nTPM
eosinophil: 22 nTPM
classical monocyte: 21 nTPM
intermediate monocyte: 14 nTPM
myeloid DC: 6.8 nTPM
total PBMC: 6.6 nTPM

Brain region

medulla oblongata: 0.8 nTPM
midbrain: 0.7 nTPM
white matter: 0.7 nTPM
amygdala: 0.6 nTPM
cerebral cortex: 0.5 nTPM
hypothalamus: 0.5 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about SIRPD.

Disease | ImmuneIEDB

Conditions an epitope on SIRPD was assayed in.

lung adenocarcinoma T 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): 1.89
gnomAD pLI: 0
gnomAD missense Z: -0.88
DepMap mean gene effect: 0.11
DepMap dependency class: none

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

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

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

SIRPD is annotated as secreted, so native SIRPD circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

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

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