The characterization of a cyclophilin-type peptidyl prolyl <i>cis</i>-<i>trans</i>-isomerase from the endoplasmic-reticulum lumen

Bose, Suchira; Mücke, Matthias; Freedman, Robert B.

doi:10.1042/bj3000871

Cited by 30 publications

(16 citation statements)

References 32 publications

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“…The sequence is aligned and compared with the N-terminal sequences of mature s-cyclophilin from chick [47], human [46,48], mouse [48] and bovine microsomes [45]. Asterisks indicate residues identical with the maize sequence ; underlining indicates conservative substitutions scoring 4 or more in the system of Feng et al [55].…”

Section: Figure 6 N-terminal Sequence Of Microsomal Ppimentioning

confidence: 99%

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Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

Sheldon¹,

Venis²

1996

Biochemical Journal

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Methods for the purification and separation of peptidyl prolyl cis-trans isomerase (PPI) from cytosolic and microsomal fractions of etiolated maize are described. On SDS/PAGE, the purified preparations appears as single polypeptides with molecular masses of 17.5 kDa and 17.7 kDa respectively. Instead of using immobilized cyclosporin A derivatives as affinity adsorbents, our methods employ conventional techniques enabling purification of the proteins on a much larger scale than previously described. An antiserum raised against the cytosolic PPI recognizes polypeptides of similar molecular mass from a wide range of plant species on an immunoblot. There is virtually no recognition of the microsomal PPI. The cytosolic and microsomal PPIs are inhibited by cyclosporin A (Ki = 6 nM in both cases), indicating that they are cyclophilins. The cytosolic enzyme is inactivated by 5 mM N-ethylmaleimide and 2 mM phenylglyoxal. N-terminal sequencing of the microsomal PPI indicates a high level of sequence similarity with the N-terminal sequence of mature animal s-cyclophilin (cyclophilin B).

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Section: Figure 6 N-terminal Sequence Of Microsomal Ppimentioning

confidence: 99%

“…CsA inhibited the activity of the microsomal enzyme with a K i estimated to be 6 nM ( Figure 3) showing that it is also a cyclophilin. It has a value of k cat \K m estimated to be 25 µM −" :s −" compared with values of 3-14 µM −" :s −" for cyclophilin B from mammals [45,46].…”

Section: Figure 6 N-terminal Sequence Of Microsomal Ppimentioning

confidence: 99%

Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

Sheldon¹,

Venis²

1996

Biochemical Journal

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“…While they are all believed to employ the ‘twisted amide’ mechanism of catalysis, as is seen with prolyl isomerization in water, the cyclophilins (Eisenmesser et al , 2002; Hur and Bruice, 2002) and parvulins (Ranganathan et al , 1997) achieve this through the use of near attack conformers, whereas the FKBPs use hydrophobic distortion (Harrison and Stein, 1992; Hur and Bruice, 2002). They are found widely distributed in eukaryotes, prokaryotes and archaea (Galat, 1993, 1999; Galat and Metcalfe, 1995; He et al , 2004; Ivery, 2000; Maruyama and Furuani, 2000; Rulten et al , 1999), implying that their function is required in cellular processes from bacteria to man, and in all the major compartments of the cell (Bose et al , 1994; Halestrap and Davidson, 1990; Handschumacher et al , 1984; Jin and Burakoff, 1993; Lu et al , 1996; Nigam et al , 1993; Siekierka et al , 1989; Uchida et al , 1999; Wang et al , 1996).…”

Section: Introductionmentioning

confidence: 99%

Identification and comparative analysis of the peptidyl‐prolyl cis/trans isomerase repertoires of H. sapiens, D. melanogaster, C. elegans, S. cerevisiae and Sz. pombe

Pemberton

Kay

2005

Comp Funct Genom

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The peptidyl-prolyl cis/trans isomerase (PPIase) class of proteins comprises three member families that are found throughout nature and are present in all the major compartments of the cell. Their numbers appear to be linked to the number of genes in their respective genomes, although we have found the human repertoire to be smaller than expected due to a reduced cyclophilin repertoire. We show here that whilst the members of the cyclophilin family (which are predominantly found in the nucleus and cytoplasm) and the parvulin family (which are predominantly nuclear) are largely conserved between different repertoires, the FKBPs (which are predominantly found in the cytoplasm and endoplasmic reticulum) are not. It therefore appears that the cyclophilins and parvulins have evolved to perform conserved functions, while the FKBPs have evolved to fill ever-changing niches within the constantly evolving organisms. Many orthologous subgroups within the different PPIase families appear to have evolved from a distinct common ancestor, whereas others, such as the mitochondrial cyclophilins, appear to have evolved independently of one another. We have also identified a novel parvulin within Drosophila melanogaster that is unique to the fruit fly, indicating a recent evolutionary emergence. Interestingly, the fission yeast repertoire, which contains no unique cyclophilins and parvulins, shares no PPIases solely with the budding yeast but it does share a majority with the higher eukaryotes in this study, unlike the budding yeast. It therefore appears that, in comparison with Schizosaccharomyces pombe, Saccharomyces cerevisiae is a poor representation of the higher eukaryotes for the study of PPIases.

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“…Like the calnexin/ calreticulin system, Hsp70 proteins are thought to undergo cycles of binding and release from unfolded proteins (Gamer et al, 1996;Bukau and Horwich, 1998), with folding occurring during the release cycle (Hendershot et al, 1996). A number of other resident ER chaperones and folding enzymes, such as GRP94 (Melnick et al, 1992;Kuznetsov et al, 1994;Chavany et al, 1996), GRP170 (Lin et al, 1993;Kuznetsov et al, 1997), ERp72 (Mazzarella et al, 1990;Lin et al, 1993;Reddy et al, 1996), protein disulfide isomerase (PDI) (Roth and Pierce, 1987;Bulleid and Freedman, 1988;Reddy et al, 1996), and peptidyl-prolyl isomerases (Bose et al, 1994;Bush et al, 1994) have been identified and shown to bind to some nascent ER proteins. However, the role of most of these proteins in ER quality control and their relationship to the two major chaperone systems have not been clearly elucidated.…”

Section: Introductionmentioning

confidence: 99%

A Subset of Chaperones and Folding Enzymes Form Multiprotein Complexes in Endoplasmic Reticulum to Bind Nascent Proteins

Meunier

Usherwood

Chung

et al. 2002

MBoC

477

406

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We demonstrate the existence of a large endoplasmic reticulum (ER)-localized multiprotein complex that is comprised of the molecular chaperones BiP; GRP94; CaBP1; protein disulfide isomerase (PDI); ERdj3, a recently identified ER Hsp40 cochaperone; cyclophilin B; ERp72; GRP170; UDP-glucosyltransferase; and SDF2-L1. This complex is associated with unassembled, incompletely folded immunoglobulin heavy chains. Except for ERdj3, and to a lesser extent PDI, this complex also forms in the absence of nascent protein synthesis and is found in a variety of cell types. Cross-linking studies reveal that the majority of these chaperones are included in the complex. Our data suggest that this subset of ER chaperones forms an ER network that can bind to unfolded protein substrates instead of existing as free pools that assembled onto substrate proteins. It is noticeable that most of the components of the calnexin/calreticulin system, which include some of the most abundant chaperones inside the ER, are either not detected in this complex or only very poorly represented. This study demonstrates an organization of ER chaperones and folding enzymes that has not been previously appreciated and suggests a spatial separation of the two chaperone systems that may account for the temporal interactions observed in other studies. INTRODUCTIONTo travel along the secretory pathway and eventually reach their appropriate cellular destinations, newly synthesized secreted and membrane-bound proteins must fold and assemble correctly. Failure to do so results in their retention in the endoplasmic reticulum (ER) and eventual degradation. The proper conformational maturation of nascent secretory pathway proteins is both aided and monitored by a number of ER chaperones and folding enzymes in a complex process termed ER quality control . The components and mechanisms of action of two major chaperone systems have been best studied. The first system is dependent on the presence of both monoglucosylated N-linked glycans and unfolded regions on nascent glycoproteins. The resident ER protein UDP-glucosyltransferase (GT) binds to the unfolded regions and adds a single glucose to the deglucosylated glycan (Trombetta and Parodi, 1992), which in turns provides the binding site for the ER chaperones calnexin and calreticulin (Sousa et al., 1992;. Cleavage of this glucose by the resident ER protein glucosidase II (Kornfeld and Kornfeld, 1985) abrogates the calnexin/calreticulin binding site (Trombetta and Parodi, 1992;Hebert et al., 1995). If during the ensuing time the nascent chain folds, UDP-GT will not rebind and the protein will be released from the ER. However, if folding is not complete or correct folding is unable to occur, the cycle will repeat itself (Sousa et al., 1992;Hebert et al., 1995).The second major ER chaperone system is only dependent on the presence of unfolded regions on proteins containing hydrophobic residues, which are recognized by the ER chaperone BiP (Flynn et al., 1991;Blond-Elguindi et al., 1993). In fact, some calnexin/calretic...

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The characterization of a cyclophilin-type peptidyl prolyl cis-trans-isomerase from the endoplasmic-reticulum lumen

Cited by 30 publications

References 32 publications

Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

Purification and characterization of cytosolic and microsomal cyclophilins from maize (Zea mays)

Identification and comparative analysis of the peptidyl‐prolyl cis/trans isomerase repertoires of H. sapiens, D. melanogaster, C. elegans, S. cerevisiae and Sz. pombe

A Subset of Chaperones and Folding Enzymes Form Multiprotein Complexes in Endoplasmic Reticulum to Bind Nascent Proteins

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