Immunophilins: for the love of proteins.
Immunophilins are chaperones that may also exhibit peptidylprolyl isomerase (PPIase) activity. This review summarizes our knowledge of the two largest families of immunophilins, namely cyclophilin and FK506-binding protein, and a novel chimeric dual-family immunophilin, named FK506- and cyclosporin-binding protein (FCBP). The larger members of each family are modular in nature, consisting of multiple PPIase and/or protein-protein interaction domains. Despite the apparent difference in their sequence and three-dimensional structure, the three families encode similar enzymatic and biological functions. Recent studies have revealed that many immunophilins possess a chaperone function independent of PPIase activity. Knockout animal studies have confirmed multiple essential roles of immunophilins in physiology and development. An immunophilin is indeed a natural 'protein-philin' (Greek 'philin' = friend) that interacts with proteins to guide their proper folding and assembly.
Barik
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Department of Biochemistry and Molecular Biology (MSB 2370), University of South Alabama, College of Medicine, 307 University Blvd., Mobile, Alabama 36688-0002, USA. sbarik@jaguar1.usouthal.edu
D000595:Amino Acid Sequence; D000818:Animals; D005260:Female; D006801:Humans; D020104:Immunophilins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D018832:Molecular Chaperones / Q000502:physiology; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship
D018832:Molecular Chaperones; D020104:Immunophilins; D019696:Peptidylprolyl Isomerase