title: Molecular characterization of cyclophilin A-like protein from Piriformospora indica for its potential role to abiotic stress tolerance in E. coli.
abstract: BACKGROUND
  Cyclophilins (CyP), conserved in all genera, are known to have regulatory responses of various cellular processes including stress tolerance. Interestingly, CyP has a crucial role as peptidyl-prolyl cis-trans isomerases (PPIases). Our earlier in silico based approach resulted into the identification of cyclophilin family from rice, Arabidopsis and yeast. In our recent report, we discovered a new OsCYP-25 from rice. Here, we identified a novel cyclophylin A-like protein (PiCyP) from Piriformospora indica which is responsible for abiotic stress tolerance in E. coli.
  
  
  RESULTS
  Cyclophylin A-like protein (CyPA) (accession number GQ214003) was selected from cDNA library. The genomic organization CyPA revealed a 1304 bp of CyPA in P. indica genome, showing 10 exons and 9 introns. Further, CyPA was evident in PCR with gDNA and cDNA and Southern blot analysis. The phylogenetic examination of CyPA of P. indica showed that it is closed to human cyclophilin. The uniqueness of PiCyPA protein was apparent in western blot study. Kinetics of purified PiCyPA protein for its PPIas activity was determined via first order rate constant (0.104 s-1) in the presence of 1 μg of PiCyPA, with increasing PiCyPA concentration, in the presence of cyclosporin A (CsA) and the inhibition constant (4.435 nM) of CsA for inhibition of PiCyPA. The differential response of E. coli harbouring pET28a-PiCypA was observed for their different degree of tolerance to different abiotic stresses as compared to empty pET28a vector.
  
  
  CONCLUSIONS
  Overexpression of PiCyPA protein E. coli cells confer enhanced tolerance to wide range of abiotic stresses. Thus, this study provides the significance of PiCypA as a molecular chaperone which advanced cellular stress responses of E. coli cells under adverse conditions, and it, furthermore, confirms the mounting the sustainability of E. coli for exploitation in recombinant proteins production. Additionally, the PiCyPA gene cooperates substantial functions in cellular network of stress tolerance mechanism, essentially required for various developmental stages, and might be a potential paramount candidate for crop improvement and its sustainable production under adverse conditions.
authors.forename: Dipesh Kumar
authors.initials: DK
authors.lastname: Trivedi
authors.forename: Mohammed Wahid
authors.initials: MW
authors.lastname: Ansari
authors.forename: Tanima
authors.initials: T
authors.lastname: Dutta
authors.forename: Prabhjeet
authors.initials: P
authors.lastname: Singh
authors.affiliation: Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg, New Delhi 110 067, India. narendra@icgeb.res.in.
authors.forename: Narendra
authors.initials: N
authors.lastname: Tuteja
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000363:Agaricales / Q000737:chemistry* / Q000201:enzymology; D000595:Amino Acid Sequence; D021984:Cyclophilin A / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005091:Exons; D005656:Fungal Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D015723:Gene Library; D005818:Genetic Engineering; D006801:Humans; D007438:Introns; D007700:Kinetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D010957:Plasmids; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological; D019076:Transgenes
chemical_list: D005656:Fungal Proteins; D021984:Cyclophilin A