<i>PTF1</i> encodes an essential protein in <i>Saccharomyces cerevisiae</i>, which shows strong homology with a new putative family of PPIases

Hani, Jean; Stumpf, G.; Domdey, Horst

doi:10.1016/0014-5793(95)00471-k

Cited by 93 publications

(113 citation statements)

References 25 publications

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“…A parvulin protein was originally found in Escherichia coli as a novel PPIase that consists of only 92 amino acids and is hence named parvulin (Latin: parvulus, very small; Rahfeld et al, 1994). Later on, parvulin homologs were found in both prokaryotic and eukaryotic organisms like SurA from E. coli (Eisenstark et al, 1992), Ess1/Ptf1 from yeast (Saccharomyces cerevisiae; Hanes et al, 1989;Hani et al, 1995), and Pin1 from human (Lu et al, 1996). Besides PPIase activity, the prokaryotic parvulins exhibit chaperonelike activities.…”

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confidence: 99%

Immunophilins and Parvulins. Superfamily of Peptidyl Prolyl Isomerases in Arabidopsis

2004

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Immunophilins are defined as receptors for immunosuppressive drugs including cyclosporin A, FK506, and rapamycin. The cyclosporin A receptors are referred to as cyclophilins (CYPs) and FK506-and rapamycin-binding proteins are abbreviated as FKBPs. These two groups of proteins (collectively called immunophilins) share little sequence homology, but both have peptidyl prolyl cis/trans isomerase (PPIase) activity that is involved in protein folding processes. Studies have identified immunophilins in all organisms examined including bacteria, fungi, animals, and plants. Nevertheless, the physiological function of immunophilins is poorly understood in any organism. In this study, we have surveyed the genes encoding immunophilins in Arabidopsis genome. A total of 52 genes have been found to encode putative immunophilins, among which 23 are putative FKBPs and 29 are putative CYPs. This is by far the largest immunophilin family identified in any organism. Both FKBPs and CYPs can be classified into single domain and multiple domain members. The single domain members contain a basic catalytic domain and some of them have signal sequences for targeting to a specific organelle. The multiple domain members contain not only the catalytic domain but also defined modules that are involved in protein-protein interaction or other functions. A striking feature of immunophilins in Arabidopsis is that a large fraction of FKBPs and CYPs are localized in the chloroplast, a possible explanation for why plants have a larger immunophilin family than animals. Parvulins represent another family of PPIases that are unrelated to immunophilins in protein sequences and drug binding properties. Three parvulin genes were found in Arabidopsis genome. The expression of many immunophilin and parvulin genes is ubiquitous except for those encoding chloroplast members that are often detected only in the green tissues. The large number of genes and diversity of structure domains and cellular localization make PPIases a versatile superfamily of proteins that clearly function in many cellular processes in plants.Immunosuppressive drugs cyclosporin A (CsA), FK506, and rapamycin are used clinically in transplantation to prevent graft rejection. During the course to understand the molecular mechanisms of immunosuppression by CsA, FK506, and rapamycin, the cellular receptors of these drugs have been purified and characterized (Schreiber, 1991;Fruman et al., 1994). CsA binds to a family of receptors named cyclophilins (CyPs), and FK506 and rapamycin bind to a distinct set of receptors called FKBPs (FK506 and rapamycin-binding proteins). Cyclophilins and FKBPs are collectively referred to as immunophilins (Schreiber, 1991).The complexes formed by immunophilins and their cognate ligands are the functional modules for immunosuppression. The FKBP12-FK506 and CyPCsA complexes, but not their separate components, bind to and inhibit the activity of calcineurin, a Ca 21 , calmodulin-dependent protein phosphatase (Liu et al., 1991). Studies have demonstrated that inhib...

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Immunophilins and Parvulins. Superfamily of Peptidyl Prolyl Isomerases in Arabidopsis

2004

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“…Among this family are the highly conserved Pin1-type PPIases (10,11), which are the only PPIases that seem to be essential for cell survival, at least in budding yeast and HeLa cells. The Pin1-type PPIases, such as the human Pin1 (11), Saccharomyces cerevisiae ESS1/Ptf1 (10,12,13), Drosophila Dodo (14), Neurospora crassa Ssp1 (15), Xenopus Pin1 (16), Aspergillus nidulans Pin1 (17), and others, consist of an amino-terminal WW domain and a carboxyl-terminal PPIase domain. WW domains, which are characterized by two invariant tryptophans, are present in a variety of signaling and regulatory proteins and were originally identified as protein interaction modules that bind to proline-rich regions in protein targets (18,19).…”

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Functional Conservation of Phosphorylation-specific Prolyl Isomerases in Plants

Yao¹,

Kops²,

Lu³

et al. 2001

Journal of Biological Chemistry

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The phosphorylation-specific peptidyl prolyl cis/trans isomerase (PPIase) Pin1 in humans and its homologues in yeast and animal species play an important role in cell cycle regulation. These PPIases consist of an NH 2 -terminal WW domain that binds to specific phosphoserine-or phosphothreonine-proline motifs present in a subset of phosphoproteins and a COOH-terminal PPIase domain that specifically isomerizes the phosphorylated serine/threonine-proline peptide bonds. Here, we describe the isolation of MdPin1, a Pin1 homologue from the plant species apple (Malus domestica) and show that it has the same phosphorylation-specific substrate specificity and can be inhibited by juglone in vitro, as is the case for Pin1. A search in the plant expressed sequence tag data bases reveals that the Pin1-type PPIases are present in various plants, and there are multiple genes in one organism, such as soybean (Glycine max) and tomato (Lycopersicon esculentum). Furthermore, all these plant Pin1-type PPIases, including AtPin1 in Arabidopsis thaliana, do not have a WW domain, but all contain a four-amino acid insertion next to the phosphospecific recognition site of the active site. Interestingly, like Pin1, both MdPin1 and AtPin1 are able to rescue the lethal mitotic phenotype of a temperature-sensitive mutation in the Pin1 homologue ESS1/PTF1 gene in Saccharomyces cerevisiae. However, deleting the extra four amino acid residues abolished the ability of AtPin1 to rescue the yeast mutation under non-overexpression conditions, indicating that these extra amino acids may be important for mediating the substrate interaction of plant enzymes. Finally, expression of MdPin1 is tightly associated with cell division both during apple fruit development in vivo and during cell cultures in vitro. These results have demonstrated that phosphorylationspecific PPIases are highly conserved functionally in yeast, animal, and plant species. Furthermore, the experiments suggest that although plant Pin1-type enzymes do not have a WW domain, they may fulfill the same functions as Pin1 and its homologues do in other organisms.

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“…Pin1 is an 18-kDA protein with orthologs that have been identified in yeast, Drosophila, Xenopus, fungi, mice, and plants (2)(3)(4)(5)(6)(7)(8). Pin1 belongs to the parvulin family of isomerases, which is distinct from the cyclophilin and FK506 binding protein peptidyl-prolyl isomerase families.…”

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confidence: 99%