Seroatlas · Human Serome Atlas

SIGLEC1

Sialoadhesin

Also known as: CD169, dJ1009E24.1, FLJ00051, FLJ00055, FLJ00073, FLJ32150, sialoadhesin, SIGLEC-1, SN, SN_HUMAN

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

Protein identityUniProt · HPA

UniProt accession: Q9BZZ2
Gene: SIGLEC1
Ensembl: ENSG00000088827
Chromosome: 20
Canonical length: 1709 aa
Protein class: CD markers, Predicted intracellular proteins, Predicted membrane proteins
Secretome location: Intracellular and membrane

OverviewNCBI Gene

This gene encodes a member of the immunoglobulin superfamily. The encoded protein is a lectin-like adhesion molecule that binds glycoconjugate ligands on cell surfaces in a sialic acid-dependent manner. It is a type I transmembrane protein expressed only by a subpopulation of macrophages and is involved in mediating cell-cell interactions. The protein plays an important role in multiple human diseases and bacterial and viral infections has been shown to enhance SARS-CoV-2 infection. [provided by RefSeq, Dec 2021]

Canonical amino-acid sequenceUniProt

1709 residues, UniProt reviewed canonical sequence.

>Q9BZZ2|SIGLEC1
     1  MGFLPKLLLL ASFFPAGQAS WGVSSPQDVQ GVKGSCLLIP CIFSFPADVE VPDGITAIWY
    61  YDYSGQRQVV SHSADPKLVE ARFRGRTEFM GNPEHRVCNL LLKDLQPEDS GSYNFRFEIS
   121  EVNRWSDVKG TLVTVTEEPR VPTIASPVEL LEGTEVDFNC STPYVCLQEQ VRLQWQGQDP
   181  ARSVTFNSQK FEPTGVGHLE TLHMAMSWQD HGRILRCQLS VANHRAQSEI HLQVKYAPKG
   241  VKILLSPSGR NILPGELVTL TCQVNSSYPA VSSIKWLKDG VRLQTKTGVL HLPQAAWSDA
   301  GVYTCQAENG VGSLVSPPIS LHIFMAEVQV SPAGPILENQ TVTLVCNTPN EAPSDLRYSW
   361  YKNHVLLEDA HSHTLRLHLA TRADTGFYFC EVQNVHGSER SGPVSVVVNH PPLTPVLTAF
   421  LETQAGLVGI LHCSVVSEPL ATLVLSHGGH ILASTSGDSD HSPRFSGTSG PNSLRLEIRD
   481  LEETDSGEYK CSATNSLGNA TSTLDFHANA ARLLISPAAE VVEGQAVTLS CRSGLSPTPD
   541  ARFSWYLNGA LLHEGPGSSL LLPAASSTDA GSYHCRARDG HSASGPSSPA VLTVLYPPRQ
   601  PTFTTRLDLD AAGAGAGRRG LLLCRVDSDP PARLQLLHKD RVVATSLPSG GGCSTCGGCS
   661  PRMKVTKAPN LLRVEIHNPL LEEEGLYLCE ASNALGNAST SATFNGQATV LAIAPSHTLQ
   721  EGTEANLTCN VSREAAGSPA NFSWFRNGVL WAQGPLETVT LLPVARTDAA LYACRILTEA
   781  GAQLSTPVLL SVLYPPDRPK LSALLDMGQG HMALFICTVD SRPLALLALF HGEHLLATSL
   841  GPQVPSHGRF QAKAEANSLK LEVRELGLGD SGSYRCEATN VLGSSNTSLF FQVRGAWVQV
   901  SPSPELQEGQ AVVLSCQVHT GVPEGTSYRW YRDGQPLQES TSATLRFAAI TLTQAGAYHC
   961  QAQAPGSATT SLAAPISLHV SYAPRHVTLT TLMDTGPGRL GLLLCRVDSD PPAQLRLLHG
  1021  DRLVASTLQG VGGPEGSSPR LHVAVAPNTL RLEIHGAMLE DEGVYICEAS NTLGQASASA
  1081  DFDAQAVNVQ VWPGATVREG QLVNLTCLVW TTHPAQLTYT WYQDGQQRLD AHSIPLPNVT
  1141  VRDATSYRCG VGPPGRAPRL SRPITLDVLY APRNLRLTYL LESHGGQLAL VLCTVDSRPP
  1201  AQLALSHAGR LLASSTAASV PNTLRLELRG PQPRDEGFYS CSARSPLGQA NTSLELRLEG
  1261  VRVILAPEAA VPEGAPITVT CADPAAHAPT LYTWYHNGRW LQEGPAASLS FLVATRAHAG
  1321  AYSCQAQDAQ GTRSSRPAAL QVLYAPQDAV LSSFRDSRAR SMAVIQCTVD SEPPAELALS
  1381  HDGKVLATSS GVHSLASGTG HVQVARNALR LQVQDVPAGD DTYVCTAQNL LGSISTIGRL
  1441  QVEGARVVAE PGLDVPEGAA LNLSCRLLGG PGPVGNSTFA WFWNDRRLHA EPVPTLAFTH
  1501  VARAQAGMYH CLAELPTGAA ASAPVMLRVL YPPKTPTMMV FVEPEGGLRG ILDCRVDSEP
  1561  LASLTLHLGS RLVASSQPQG APAEPHIHVL ASPNALRVDI EALRPSDQGE YICSASNVLG
  1621  SASTSTYFGV RALHRLHQFQ QLLWVLGLLV GLLLLLLGLG ACYTWRRRRV CKQSMGENSV
  1681  EMAFQKETTQ LIDPDAATCE TSTCAPPLG

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against SIGLEC1 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: 1
Mean surface accessibility (rSASA): 0.32
Highest tissue expression: 22 nTPM

Expression across tissuesHPA

Tissue

adipose tissue: 22 nTPM
spleen: 18 nTPM
placenta: 18 nTPM
lung: 16 nTPM
adrenal gland: 13 nTPM
lymph node: 12 nTPM

Single-cell type

kupffer cells: 296 nCPM
hofbauer cells: 227 nCPM
macrophages: 120 nCPM
monocytes: 20 nCPM
cdc: 13 nCPM
epicardial cells: 6.8 nCPM

Immune cell

classical monocyte: 1.5 nTPM
intermediate monocyte: 0.9 nTPM
myeloid DC: 0.7 nTPM
plasmacytoid DC: 0.4 nTPM
total PBMC: 0.4 nTPM
basophil: 0 nTPM

Brain region

pons: 21 nTPM
thalamus: 21 nTPM
medulla oblongata: 18 nTPM
choroid plexus: 13 nTPM
cerebral cortex: 7.6 nTPM
spinal cord: 7.2 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): 1.23
gnomAD pLI: 0
gnomAD missense Z: -0.28
DepMap mean gene effect: -0.09
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

cell-cell adhesion
cell-matrix adhesion
inflammatory response
negative regulation of type I interferon production
clathrin-dependent endocytosis of virus by host cell

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of SIGLEC1 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 SIGLEC1 as an antibody target. Whether an autoantibody or antibody against SIGLEC1 could matter depends on whether native SIGLEC1 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

SIGLEC1 is annotated at the cell surface, where native SIGLEC1 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 SIGLEC1 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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