title: The human choline acetyltransferase gene encodes two proteins.
abstract: Both 2,500- and 6,000-nucleotide (nt) mRNAs are generated by alternative splicing of the primary transcript from the human gene for choline acetyltransferase (ChAT), the 68-kDa enzyme that synthesizes acetylcholine. In vitro translation of cRNA derived from a clone of the 2,500-nt mRNA produced a protein with ChAT activity demonstrating that this transcript encodes the human ChAT enzyme. An antibody directed against a unique amino acid sequence predicted from the 6,000-nt ChAT gene transcript identified a 27-kDa protein on immunoblots of human nucleus basalis proteins. This protein was further shown to cross-react with antibodies prepared against the 68-kDa human ChAT enzyme. Gel-filtration chromatography of human nucleus basalis proteins demonstrated that the 27-kDa protein does not have ChAT activity, which eluted as a single peak coincident with that of the 68-kDa enzyme. The 27-kDa protein was, however, shown to colocalize with the ChAT enzyme in cholinergic neurons of the human spinal cord using immunohistochemical techniques.
authors.affiliation: Department of Molecular and Cellular Pharmacology, University of Miami School of Medicine, FL 33101, USA.
authors.forename: D D
authors.initials: DD
authors.lastname: Grosman
authors.forename: M V
authors.initials: MV
authors.lastname: Lorenzi
authors.forename: A C
authors.initials: AC
authors.lastname: Trinidad
authors.forename: W L
authors.initials: WL
authors.lastname: Strauss
mesh_terms: D000595:Amino Acid Sequence; D002795:Choline O-Acetyltransferase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D005796:Genes; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009474:Neurons / Q000378:metabolism; D010275:Parasympathetic Nervous System / Q000166:cytology / Q000201:enzymology; D014176:Protein Biosynthesis
chemical_list: D007527:Isoenzymes; D002795:Choline O-Acetyltransferase