Class A basic helix-loop-helix protein 15

Class A basic helix-loop-helix protein 15 (bHLHa15) also known as class B basic helix-loop-helix protein 8 (bHLHb8) or muscle, intestine and stomach expression 1 (MIST-1) is a protein that in humans is encoded by the BHLHA15 gene.

BHLHA15
Identifiers
Aliases	BHLHA15, BHLHB8, MIST1, basic helix-loop-helix family member a15
External IDs	OMIM: 608606; MGI: 891976; HomoloGene: 7838; GeneCards: BHLHA15; OMA:BHLHA15 - orthologs
Gene location (Human) Chr. Chromosome 7 (human) Band 7q21.3 Start 98,211,439 bp End 98,215,457 bp
Gene location (Mouse) Chr. Chromosome 5 (mouse) Band 5|5 G2 Start 144,127,104 bp End 144,131,259 bp
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in parotid gland body of pancreas bone marrow cells body of stomach testicle olfactory zone of nasal mucosa trachea prostate minor salivary glands cardia Top expressed in submandibular gland lacrimal gland parotid gland seminal vesicula pancreas crypt of lieberkuhn of small intestine Paneth cell epithelium of stomach islet of Langerhans pyloric antrum More reference expression data BioGPS n/a
Gene ontology Molecular function DNA-binding transcription activator activity, RNA polymerase II-specific DNA binding RNA polymerase II transcription regulatory region sequence-specific DNA binding protein homodimerization activity protein dimerization activity DNA-binding transcription factor activity, RNA polymerase II-specific Cellular component nucleus Biological process endoplasmic reticulum unfolded protein response cell-cell signaling G protein-coupled receptor signaling pathway cellular response to glucose starvation intracellular distribution of mitochondria regulation of transcription, DNA-templated cell maturation transcription by RNA polymerase II mitochondrial calcium ion transmembrane transport Golgi organization glucose homeostasis transcription, DNA-templated negative regulation of myotube differentiation calcium-mediated signaling positive regulation of transcription by RNA polymerase II Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 168620 17341 Ensembl ENSG00000180535 ENSMUSG00000052271 UniProt Q7RTS1 Q9QYC3 RefSeq (mRNA) NM_177455 NM_010800 RefSeq (protein) NP_803238 NP_034930 Location (UCSC) Chr 7: 98.21 – 98.22 Mb Chr 5: 144.13 – 144.13 Mb PubMed search
Wikidata
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Function

bHLHa15 is required developmentally for the proper organization of all protein secreting, serous exocrine glands. In the absence of Mist1, exocrine tissue shows improper organization of organelles, especially the localization of the zymogen granules. The zymogen granules are the vesicles that store enzymes near the plasma membrane for easy release when stimulated. This disorganization caused by the loss of Mist1 leads to increased susceptibility toward pancreatic damage and potentially pancreatic cancer.

Further reading

• Lemercier C, To RQ, Swanson BJ, et al. (1997). "Mist1: a novel basic helix-loop-helix transcription factor exhibits a developmentally regulated expression pattern". Dev. Biol. 182 (1): 101–13. doi:10.1006/dbio.1996.8454. PMID 9073453.
• Lemercier C, To RQ, Carrasco RA, Konieczny SF (1998). "The basic helix-loop-helix transcription factor Mist1 functions as a transcriptional repressor of myoD". EMBO J. 17 (5): 1412–22. doi:10.1093/emboj/17.5.1412. PMC 1170489. PMID 9482738.
• Pin CL, Lemercier C, Konieczny SF (2000). "Cloning of the murine Mist1 gene and assignment to mouse chromosome band 5G2-5G3". Cytogenet. Cell Genet. 86 (3–4): 219–22. doi:10.1159/000015342. PMID 10575209. S2CID 42840963.
• Pin CL, Rukstalis JM, Johnson C, Konieczny SF (2001). "The bHLH transcription factor Mist1 is required to maintain exocrine pancreas cell organization and acinar cell identity". J. Cell Biol. 155 (4): 519–30. doi:10.1083/jcb.200105060. PMC 2198859. PMID 11696558.
• Zhao Y, Johansson C, Tran T, et al. (2006). "Identification of a basic helix-loop-helix transcription factor expressed in mammary gland alveolar cells and required for maintenance of the differentiated state". Mol. Endocrinol. 20 (9): 2187–98. doi:10.1210/me.2005-0214. PMID 16645041.