title: Distinct light-, stress-, and nutrient-dependent regulation of multiple tryptophan-rich sensory protein (TSPO) genes in the cyanobacterium Fremyella diplosiphon.
abstract: The cyanobacterium Fremyella diplosiphon possesses 3 genes encoding homologs of the tryptophan-rich sensory protein (TSPO). TSPO proteins are membrane proteins implicated in stress responses across a range of organisms from bacteria to humans. Diverse TSPO proteins appear to generally bind tetrapyrrole ligands. Previously, we reported that one of these homologs, FdTSPO1, is involved in salt-, osmotic- and oxidative stress responses in F. diplosiphon. Here, we show distinct regulation of cellular mRNA levels of all 3 FdTSPO homologs by different abiotic stresses. Given the prior finding that all 3 FdTSPO proteins are capable of binding tetrapyrroles of functional relevance in F. diplosiphon and the observation of a ligand-dependent functional role for FdTSPO1 in vivo, FdTSPO1, FdTSPO2, and FdTSPO3 appear to have distinct, yet overlapping, roles in vivo. We propose that these proteins regulate tetrapyrrole homeostasis and/or tetrapyrrole-modulated functions in F. diplosiphon in response to multiple environmental stresses.
authors.affiliation: a Department of Energy - Plant Research Laboratory , Michigan State University , East Lansing , Michigan , USA.
authors.forename: Andrea W U
authors.initials: AW
authors.lastname: Busch
authors.affiliation: a Department of Energy - Plant Research Laboratory , Michigan State University , East Lansing , Michigan , USA.|b Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan , USA.|c Department of Microbiology and Molecular Genetics , Michigan State University , East Lansing , Michigan , USA.
authors.forename: Beronda L
authors.initials: BL
authors.lastname: Montgomery
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D000458:Cyanobacteria / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects; D008027:Light; D009584:Nitrogen / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D009584:Nitrogen
keywords: Abiotic stress; cyanobacteria; diurnal; light; nitrogen availability; stress regulation; temperature; tryptophan-rich sensory protein (TSPO)