title: Mechanism of cyst specific protein 21 mRNA induction during Acanthamoeba differentiation.
abstract: The Acanthamoeba cyst specific protein 21 (CSP21) gene is tightly repressed in growing cells and highly induced early during differentiation into a dormant cyst. This increase is mediated by the rate of transcription of the CSP21 gene as determined by nuclear run-on assays. The promoter region of the CSP21 gene was analyzed by transcript start site mapping and in vitro transcription of wild-type or mutant templates, using extracts from growing cells. A sequence located 3' to a modified TATA box completely inhibits transcription and removal of this region permits robust transcription utilizing a start site approximately 35 base pairs downstream of the TATA box. Sequences 5' to the TATA box had no effect on transcription, suggesting that anti-repression is the only mechanism required for CSP21 induction. Fractionation of nuclear extracts yielded a fraction capable of transcription from the CSP21 promoter, and a fraction containing a promoter-specific repressing activity. Anti-repression may thus be a major mechanism regulating differentiation or maintenance of the proliferative cycle in Acanthamoeba.
authors.affiliation: Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, University of Vermont, Burlington, VT 05405, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.forename: Tom
authors.initials: T
authors.lastname: Orfeo
authors.forename: Greg
authors.initials: G
authors.lastname: Gilmartin
authors.forename: Erik
authors.initials: E
authors.lastname: Bateman
mesh_terms: D000048:Acanthamoeba / Q000235:genetics* / Q000254:growth & development; D000818:Animals; D005809:Genes, Regulator; D011401:Promoter Regions, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D016385:TATA Box; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D020506:Untranslated Regions
chemical_list: C112973:CSP21 protein, Acanthamoeba castellanii; D015800:Protozoan Proteins; D012333:RNA, Messenger; D020506:Untranslated Regions