View source for Biology:Sialic acid-binding Ig-like lectin 12

{{Short description|Protein-coding gene in the species Homo sapiens}}
{{Infobox_gene}}
'''Sialic acid-binding Ig-like lectin 12''', or '''Siglec-XII''', is a [[Biology:Protein|protein]] that in humans, is encoded by the ''SIGLEC12'' [[Biology:Gene|gene]].<ref name="pmid11409877">{{cite journal | vauthors = Foussias G, Taylor SM, Yousef GM, Tropak MB, Ordon MH, Diamandis EP | title = Cloning and molecular characterization of two splice variants of a new putative member of the Siglec-3-like subgroup of Siglecs | journal = Biochem Biophys Res Commun | volume = 284 | issue = 4 | pages = 887–99 |date=Jun 2001 | pmid = 11409877 | doi = 10.1006/bbrc.2001.5052 }}</ref><ref name="pmid11328818">{{cite journal | vauthors = Yu Z, Lai CM, Maoui M, Banville D, Shen SH | title = Identification and characterization of S2V, a novel putative siglec that contains two V set Ig-like domains and recruits protein-tyrosine phosphatases SHPs | journal = J Biol Chem | volume = 276 | issue = 26 | pages = 23816–24 |date=Jun 2001 | pmid = 11328818 | doi = 10.1074/jbc.M102394200 | doi-access = free }}</ref><ref name="entrez"/>

[[Chemistry:Sialic acid|Sialic acid]]-binding immunoglobulin-like [[Biology:Lectin|lectin]]s (SIGLECs) are a family of cell surface [[Biology:Protein|protein]]s belonging to the [[Biology:Immunoglobulin superfamily|immunoglobulin superfamily]]. They mediate protein-carbohydrate interactions by selectively binding to different [[Chemistry:Sialic acid|sialic acid]] moieties present on [[Biology:Glycolipid|glycolipid]]s and [[Chemistry:Glycoprotein|glycoprotein]]s. This gene encodes a member of the SIGLEC3-like subfamily of SIGLECs. Members of this subfamily are characterized by an extracellular V-set immunoglobulin-like domain followed by two C2-set immunoglobulin-like domains, and the cytoplasmic tyrosine-based motifs, ITIM and SLAM-like. 

The encoded protein, upon tyrosine phosphorylation, has been shown to recruit the Src homology 2 domain-containing protein-tyrosine phosphatases SHP1 and SHP2. It has been suggested that the protein is involved in the negative regulation of  [[Biology:Macrophage|macrophage]] signaling by functioning as an inhibitory [[Biology:Receptor (biochemistry)|receptor]]. This gene is located in a cluster with other SIGLEC3-like genes on 19q13.4. 

Alternatively spliced transcript variants encoding distinct isoforms have been described for this gene.<ref name="entrez">
{{cite web | title = Entrez Gene: SIGLEC12 sialic acid binding Ig-like lectin 12| url = https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=89858}}</ref>

The Siglec-XII protein has been identified as a possible promoter of human carcinoma progression in research by Ajit Varki and Nissi Varki at the University of California San Diego School of Medicine.<ref>S.S. Siddiqui et al., ''Human-specific polymorphic pseudogenization of SIGLEC12 protects against advanced cancer progression'', FASEB BioAdvances, 3:69–82, 2021</ref> Approximately seventy percent of humans have a mutation that inactivates the protein, but those without the mutation may suffer an inordinate number of carcinomas when compared to other primates.<ref> Jones, Asher, ''[https://www.the-scientist.com/the-literature/rogue-protein-could-contribute-to-humans-high-cancer-rates-68576 “Rogue” Protein Could Contribute to Humans’ High Cancer Rates]'', The Scientist, April 1, 2021</ref> The research is being conducted to determine whether inactivation of the gene might deter its promotional effect upon the progression of human carcinoma.
==References==
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==Further reading==
{{refbegin | 2}}
*{{cite journal  | vauthors=Maruyama K, Sugano S |title=Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides. |journal=Gene |volume=138 |issue= 1–2 |pages= 171–4 |year= 1994 |pmid= 8125298 |doi=10.1016/0378-1119(94)90802-8  }}
*{{cite journal   |vauthors=Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, etal |title=Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library |journal=Gene |volume=200 |issue= 1–2 |pages= 149–56 |year= 1997 |pmid= 9373149 |doi=10.1016/S0378-1119(97)00411-3  }}
*{{cite journal  | vauthors=Angata T, Varki NM, Varki A |title=A second uniquely human mutation affecting sialic acid biology |journal=J. Biol. Chem. |volume=276 |issue= 43 |pages= 40282–7 |year= 2001 |pmid= 11546777 |doi= 10.1074/jbc.M105926200 |doi-access= free }}
*{{cite journal   |vauthors=Strausberg RL, Feingold EA, Grouse LH, etal |title=Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue= 26 |pages= 16899–903 |year= 2003 |pmid= 12477932 |doi= 10.1073/pnas.242603899  | pmc=139241 |bibcode=2002PNAS...9916899M |doi-access=free }}
*{{cite journal   |vauthors=Clark HF, Gurney AL, Abaya E, etal |title=The Secreted Protein Discovery Initiative (SPDI), a Large-Scale Effort to Identify Novel Human Secreted and Transmembrane Proteins: A Bioinformatics Assessment |journal=Genome Res. |volume=13 |issue= 10 |pages= 2265–70 |year= 2003 |pmid= 12975309 |doi= 10.1101/gr.1293003  | pmc=403697 }}
*{{cite journal   |vauthors=Ota T, Suzuki Y, Nishikawa T, etal |title=Complete sequencing and characterization of 21,243 full-length human cDNAs |journal=Nat. Genet. |volume=36 |issue= 1 |pages= 40–5 |year= 2004 |pmid= 14702039 |doi= 10.1038/ng1285 |doi-access= free }}
*{{cite journal   |vauthors=Gerhard DS, Wagner L, Feingold EA, etal |title=The Status, Quality, and Expansion of the NIH Full-Length cDNA Project: The Mammalian Gene Collection (MGC) |journal=Genome Res. |volume=14 |issue= 10B |pages= 2121–7 |year= 2004 |pmid= 15489334 |doi= 10.1101/gr.2596504  | pmc=528928 }}
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{{Lectins}}


{{Sourceattribution|Sialic acid-binding Ig-like lectin 12}}