2015 Vol.1 No.1:7 iMedPub Journals www.imedpub.com Commentary 1 Biochemistry & Molecular Biology Journal ISSN 2471-8084 © Under License of Creative Commons Attribution 3.0 License | This article is available in: http://biochem-molbio.imedpub.com/archive.php DOI: 10.21767/2471-8084.100007 Dipesh Kumar Trivedi 1,3 , Sarvajeet Singh Gill 2 , Neel Sarovar Bhavesh 1 , Ashutosh Kumar 3 and Narendra Tuteja 4 1 Internatonal Centre for Genetc Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Marg New Delhi, India 2 Centre for Biotechnology, MD University, Rohtak, Haryana, India 3 Department of Biosciences & Bioengineering Indian Insttute of Technology Bombay, Mumbai, India 4 Amity Insttute of Microbial Technology, Amity University, Noida, India Corresponding author: Dr. Sarvajeet Singh Gill  ssgill14@yahoo.co.in Centre for Biotechnology, MD University, Rohtak, Haryana, India Tel: 01262393596 Citation: Trivedi DK, Gill SS, Bhavesh NS. Cyclophilin: A Versatle Chaperone of Biological System. Biochem Mol Biol J. 2016, 1:1. The functonal cellular proteome machinery depends on the protein folding and unfolding within the cell. The primary amino acid sequence and the chaperone actvity play a signifcant role in proper protein folding [1]. Chaperone interacts with nascent polypeptde and helps in proper folding and formaton of stable protein complexes [2]. Molecular chaperone prevents inappropriate inter- and intra-molecular interactons among polypeptdes. Immunophilins are the receptors for immunosuppressant drug consist of two large groups of proteins called ‘cyclophilins’ (receptors for cyclosporine A, CYPs) and FK506- binding proteins (FKBPs). Cyclophilins are ubiquitous proteins found to be present in all organisms ranging from bacteria to mammals [3]. Cyclophilins are involved in a wide range of cellular processes like protein folding, protein complex stabilizaton, cell division, protein trafcking, cell signalling, transcriptonal regulaton, pre-mRNA splicing and stress tolerance [4,5]. Cyclophilin are known as peptdyl-prolyl isomerase (PPIase) having PPIase domain which is conserved among all species. The peptdyl-prolyl isomerase (E.C. 35.1.2.8) is involved in catalysis of cis-trans isomerisaton of proline residues [3]. The exact molecular mechanism and biological functon of the PPIase actvity of cyclophilin stll remains unclear. All cyclophilins having conserved PPIase domain with the excepton of some mult-domain cyclophilin proteins comprised of domains like WD domain (of CYP71 in Arabidopsis, LOC_Os08g44330 in Rice), leucine (Leu) zipper and phosphatase binding domain (in thylakoid lumen- localized cyclophilin TLP40) [6]. The Arabidopsis cyclophilin CYP38 does not display any PPIase actvity despite of having a PPIase domain. CYP38 is essental for the proper folding of D1 protein and CP43 of photosystem II and correct assembly of the oxygen evolving complex [7]. It has been reported that Arabidopsis with mutated CYP38 is susceptble against photoinhibiton. WD40 domain containing CYP71 in Arabidopsis plays a key role in gene repression and organogenesis and acts as a histone remodelling factor which ultmately leads to chromatn based gene silencing [8]. The tetratricopeptde repeat (TPR) motf containing CYP40 in mammals interacts with hsp-90, indicatng the crucial role played by these proteins in signalling [9]. All cyclophilins contain conserved cyclophilin-like domain (CLD) of approximately 109 amino acids. Cyclophilins were known to be ubiquitous proteins found in all systems such as mammals, plants, fungi and bacteria. These proteins are highly conserved with respect to PPIase actvity from the evolutonary point of view. There are 28 and 35 Cyclophilin: A Versatle Chaperone of Biological System Received: December 11, 2015; Accepted: December 13, 2015; Published: December 16, 2015 cyclophilins in rice and Arabidopsis respectvely [4]. In humans, 7 major cyclophilins have been reported- hCyp18 (CypA), hCyp22 (CypB), hCypC, hCypD, hCyp40 (hCypE) and hCypNK (identfed in natural killer cells). In Saccharomyces cerevisiae,8 cyclophilins have been identfed, named Cpr1-Cpr8 [4] whereas, in Drosophila, 9 cyclophilins have been identfed. The crystal structure of AtCyp38 and PiCypA from Arabidopsis thaliana and Piriformospora indica respectvely, showed that it is a monomeric single domain protein and forms a canonical cyclophilin fold comprising two α-helices and eight β-strands [5,7]. Eight β-strands form a fatened cylinder with β-barrel-like fold where two helices sit on the top and botom of the barrel. The molecular structure of the proline residue allows the Xaa-Pro peptde bond (where Xaa is any amino acid residue) to adopt a ‘cis’ conformaton [10]. Cyclophilins are ubiquitous proteins which consist of peptdyl- prolyl cis/transisomerase (PPIase) actvity and perform important