Butyrophilin, subfamily 1, member A1

BTN1A1
Identifiers
Aliases	BTN1A1, BT, BTN, BTN1, butyrophilin subfamily 1 member A1
External IDs	OMIM: 601610; MGI: 103118; HomoloGene: 1312; GeneCards: BTN1A1; OMA:BTN1A1 - orthologs
Gene location (Human) Chr. Chromosome 6 (human) Band 6p22.2 Start 26,500,303 bp End 26,510,425 bp
Gene location (Mouse) Chr. Chromosome 13 (mouse) Band 13 A3.1|13 9.72 cM Start 23,641,162 bp End 23,650,071 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in gonad lymph node appendix tonsil spleen blood granulocyte urinary bladder C1 segment duodenum Top expressed in lactiferous gland ascending aorta female urethra aortic valve embryo atrioventricular junction endocardial cushion Paneth cell gastrula atrioventricular valve More reference expression data BioGPS More reference expression data
Gene ontology Molecular function signaling receptor binding signaling receptor activity Cellular component integral component of membrane extracellular region integral component of plasma membrane membrane extracellular space plasma membrane external side of plasma membrane Biological process regulation of immune response T cell receptor signaling pathway Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 696 12231 Ensembl ENSG00000124557 ENSMUSG00000000706 UniProt Q13410 Q62556 RefSeq (mRNA) NM_001732 NM_013483 RefSeq (protein) NP_001723 NP_038511 Location (UCSC) Chr 6: 26.5 – 26.51 Mb Chr 13: 23.64 – 23.65 Mb PubMed search
Wikidata
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Butyrophilin subfamily 1 member A1 is a protein that in humans is encoded by the BTN1A1 gene.

Butyrophilin (BTN) is the major protein associated with fat droplets in the milk. It is a member of the immunoglobulin superfamily. It may have a cell surface receptor function. The human butyrophilin gene is localized in the major histocompatibility complex (MHC) class I region of 6p and may have arisen relatively recently in evolution by the shuffling of exons between 2 ancestral gene families

Function

Btn1a1 regulates the amount of lipids and size of droplets expressed in milk. When the gene is compromised in laboratory mice, approximately half the pups died within the first 20 days and the remainder were significantly under-weight.

Link to multiple sclerosis

Butyrophilin has been presented as a potential antigen which may be similar enough to myelin oligodendrocyte glycoprotein (MOG) to spur the immune system to attack myelin in a process known as molecular or epitopic mimicry. This suggests that ingestion of butyrophilin in dairy products from cows and goats may be a potential trigger for multiple sclerosis. Independent studies by a group in Germany have reached similar conclusions.

The German group have used heavy doses of butyrophilin on mice with an experimental model for multiple sclerosis called EAE. They have found that this strategy, called immune tolerance, reduces the effects of the disease.

External links

• Human BTN1A1 genome location and BTN1A1 gene details page in the UCSC Genome Browser.

Further reading

• Mather IH, Jack LJ (1994). "A review of the molecular and cellular biology of butyrophilin, the major protein of bovine milk fat globule membrane". J. Dairy Sci. 76 (12): 3832–50. doi:10.3168/jds.s0022-0302(93)77726-7. PMID 8132890.
• Heid HW, Winter S, Bruder G, et al. (1983). "Butyrophilin, an apical plasma membrane-associated glycoprotein characteristic of lactating mammary glands of diverse species". Biochim. Biophys. Acta. 728 (2): 228–38. doi:10.1016/0005-2736(83)90476-5. PMID 6830779.
• Sato T, Takio K, Kobata A, et al. (1995). "Site-specific glycosylation of bovine butyrophilin". J. Biochem. 117 (1): 147–57. doi:10.1093/oxfordjournals.jbchem.a124702. PMID 7775382.
• Taylor MR, Peterson JA, Ceriani RL, Couto JR (1996). "Cloning and sequence analysis of human butyrophilin reveals a potential receptor function". Biochim. Biophys. Acta. 1306 (1): 1–4. doi:10.1016/0167-4781(19)60000-x. PMID 8611614.
• Cavaletto M, Giuffrida MG, Giunta C, et al. (1999). "Multiple forms of lactadherin (breast antigen BA46) and butyrophilin are secreted into human milk as major components of milk fat globule membrane". J. Dairy Res. 66 (2): 295–301. doi:10.1017/s0022029999003507. PMID 10376248. S2CID 29228427.
• Shibui A, Tsunoda T, Seki N, et al. (1999). "Cloning, expression analysis, and chromosomal localization of a novel butyrophilin-like receptor". J. Hum. Genet. 44 (4): 249–52. doi:10.1007/s100380050153. PMID 10429365.
• Rhodes DA, Stammers M, Malcherek G, et al. (2001). "The cluster of BTN genes in the extended major histocompatibility complex". Genomics. 71 (3): 351–62. doi:10.1006/geno.2000.6406. PMID 11170752.
• McManaman JL, Palmer CA, Wright RM, Neville MC (2003). "Functional regulation of xanthine oxidoreductase expression and localization in the mouse mammary gland: evidence of a role in lipid secretion". J. Physiol. 545 (Pt 2): 567–79. doi:10.1113/jphysiol.2002.027185. PMC 2290700. PMID 12456835.
• Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. Bibcode:2002PNAS...9916899M. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
• Mungall AJ, Palmer SA, Sims SK, et al. (2003). "The DNA sequence and analysis of human chromosome 6". Nature. 425 (6960): 805–11. Bibcode:2003Natur.425..805M. doi:10.1038/nature02055. PMID 14574404.
• Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334.
• Woo JS, Imm JH, Min CK, et al. (2006). "Structural and functional insights into the B30.2/SPRY domain". EMBO J. 25 (6): 1353–63. doi:10.1038/sj.emboj.7600994. PMC 1422157. PMID 16498413.