Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2013 Jan;8(1):e22734.
doi: 10.4161/psb.22734. Epub 2012 Nov 3.

Cyclophilins: proteins in search of function

Affiliations
Review

Cyclophilins: proteins in search of function

Sumita Kumari et al. Plant Signal Behav. 2013 Jan.

Abstract

Cyclophilins constitute a subgroup of large family of proteins called immunophilins, which also include FKBPs and Parvulins. They are remarkably conserved in all genera, highlighting their pivotal role in important cellular processes. Most cyclophilins display PPIase enzymatic activity, multiplicity, diverse cellular locations and active role in protein folding which render them to be included in the class of diverse set of proteins called molecular chaperones. Due to their distinct PPIase function, besides protein disulfide isomerases and protein foldases, cyclophilins have been deemed necessary for in vivo chaperoning activity. Unlike other cellular chaperones, these proteins are specific in their respective targets. Not all cyclophilin proteins possess PPIase activity, indicating a loss of their PPIase activity during the course of evolution and gain of function independent of their PPIase activity. The PPIase function of cyclophilins is also compensated by their functional homologs, like FKBPs. Multiple cyclophilin members in plants like Arabidopsis and rice have been reported to be associated with diverse functions and regulatory pathways through their foldase, scaffolding, chaperoning or other unknown activities. Although many functions of plant cyclophilins were reported or suggested, the physiological relevance and molecular basis of stress-responsive expression of plant cyclophilins is still largely unknown. However, their wide distribution and ubiquitous nature signifies their fundamental importance in plant survival. Several of these members have also been directly linked to multiple stresses. This review attempts to deal with plant cyclophilins with respect to their role in stress response.

Keywords: cyclophilin; protein folding; stress.

PubMed Disclaimer

Figures

None
Figure 1. A schematic illustration of the trans and cis isomers of the peptidyl prolyl bond. The interconversion between the two forms is catalyzed by cyclophilins and other peptidyl-prolyl isomerases (PPIases).
None
Figure 2. A hypothetical model for cyclophilin mediated stress protective mechanism operative at cellular level. Cyclophilin proteins possibly employ diverse strategies to prevent stress-induced injury via its gene regulatory and repair pathways.

References

    1. Galat A. Peptidylprolyl cis/trans isomerases (immunophilins): biological diversity--targets--functions. Curr Top Med Chem. 2003;3:1315–47. doi: 10.2174/1568026033451862. - DOI - PubMed
    1. Harding MW, Galat A, Uehling DE, Schreiber SL. A receptor for the immunosuppressant FK506 is a cis-trans peptidyl-prolyl isomerase. Nature. 1989;341:758–60. doi: 10.1038/341758a0. - DOI - PubMed
    1. Hennig L, Christner C, Kipping M, Schelbert B, Rücknagel KP, Grabley S, et al. Selective inactivation of parvulin-like peptidyl-prolyl cis/trans isomerases by juglone. Biochemistry. 1998;37:5953–60. doi: 10.1021/bi973162p. - DOI - PubMed
    1. Handschumacher RE, Harding MW, Rice J, Drugge RJ, Speicher DW. Cyclophilin: a specific cytosolic binding protein for cyclosporin A. Science. 1984;226:544–7. doi: 10.1126/science.6238408. - DOI - PubMed
    1. Fischer G, Bang H, Mech C. [Determination of enzymatic catalysis for the cis-trans-isomerization of peptide binding in proline-containing peptides] Biomed Biochim Acta. 1984;43:1101–11. - PubMed

Publication types

MeSH terms

LinkOut - more resources