title: A cyclophilin from Griffithsia japonica has thermoprotective activity and is affected by CsA.
abstract: Members of the multifunctional Cyp family have been isolated from a wide range of organisms. However, few functional studies have been performed on the role of these proteins as chaperones in red alga. For studying the function of cDNA GjCyp-1 isolated from the red alga (Griffithsia japonica), we expressed and purified a recombinant GjCyp-1 containing a hexahistidine tag at the amino-terminus in Escherichia coli. An expressed fusion protein, H6GjCyp-1 maintained the stability of E. coli proteins up to 50 degrees C. For a functional bioassay for recombinant H6GjCyp-1, the viability of E. coli cells overexpressing H6GjCyp-1 was compared with that of cells not expressing H6GjCyp-1 at 50 degrees C. After high temperature treatment for 1 h, E. coli overexpressing H6GjCyp-1 survived about three times longer than E. coli lacking H6GjCyp-1. Measurement of the light scattering of luciferase (luc) showed that GjCyp-1 prevents the aggregation of luc during mild heat stress and that the thermoprotective activity of GjCyp-1 is blocked by cyclosporin A (CsA), an inhibitor of Cyps. Furthermore, the Cyp-CsA complex inhibited the growth of E. coli under normal conditions. The results of the GjCyp-1 bioassays as well as in vitro studies strongly suggest that Cyp confers thermotolerance to E. coli.
authors.affiliation: Institute of Molecular Biology and Genetics, Seoul National University, Seoul 151-742, Korea. choeun@snu.ac.kr
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Cho
authors.forename: Yoo Kyung
authors.initials: YK
authors.lastname: Lee
authors.forename: Choo Bong
authors.initials: CB
authors.lastname: Hong
mesh_terms: D003001:Cloning, Molecular; D021983:Cyclophilins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016572:Cyclosporine / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D005822:Genetic Vectors; D006639:Histidine / Q000737:chemistry / Q000235:genetics; D008156:Luciferases / Q000502:physiology; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics; D017510:Protein Folding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D000461:Rhodophyta / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013696:Temperature; D013997:Time Factors
chemical_list: C471213:His-His-His-His-His-His; D018832:Molecular Chaperones; D009842:Oligopeptides; D011993:Recombinant Fusion Proteins; D006639:Histidine; D016572:Cyclosporine; D008156:Luciferases; D021983:Cyclophilins