Misplaced Pages

#469530

14-647: PPIE may refer to: PPIE (gene) Panama–Pacific International Exposition , 1915 world's fair in California Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title PPIE . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=PPIE&oldid=928357029 " Category : Disambiguation pages Hidden categories: Short description

28-447: A cyclophilin, PPI binds cyclosporin A (CsA) and can be found within the cell or secreted by the cell. In eukaryotes, cyclophilins localize ubiquitously to many cell and tissue types. In addition to PPIase and protein chaperone activities, cyclophilins function in mitochondrial metabolism, apoptosis, immunological response, inflammation, and cell growth and proliferation. PPIE in particular also exhibits RNA-binding activity. Due to

42-441: A protein folding event include: It is important to note that not every proline peptide bond is critical to the structure or function of a protein, and not every such bond has a significant influence on folding kinetics, especially trans bonds. Furthermore, some prolyl isomerases have a degree of sequence specificity and therefore may not catalyze the isomerization of prolines in certain sequence contexts. Prolyl isomerase activity

56-596: A β-barrel structure with a hydrophobic core. This β-barrel is composed of eight anti-parallel β-strands and capped by two α-helices at the top and bottom. In addition, the β-turns and loops in the strands contribute to the flexibility of the barrel. In particular, PPIE contains two RNA-binding domains at the N-terminal and a 165-bases long PPIase domain at the C-terminal. The PPIase domain is homologous to PPIA and can be bound and inhibited by CsA. The protein encoded by this gene

70-512: Is a member of the peptidyl-prolyl cis-trans isomerase ( PPIase ) family. PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Generally, PPIases are found in all eubacteria and eukaryotes, as well as in a few archaebacteria, and thus are highly conserved. The PPIase family is further divided into three structurally distinct subfamilies: cyclophilin (CyP), FK506-binding protein ( FKBP ), and parvulin (Pvn). As

84-640: Is an enzyme which in humans is encoded by the PPIE gene on chromosome 1. As a member of the peptidyl-prolyl cis-trans isomerase (PPIase) family, this protein catalyzes the cis-trans isomerization of proline imidic peptide bonds , which allows it to facilitate folding or repair of proteins. In addition, PPIE participates in many biological processes, including mitochondrial metabolism , apoptosis , and inflammation , as well as related diseases and conditions, such as ischemic reperfusion injury , AIDS , influenza , and cancer . Like other cyclophilins, PPIE forms

98-494: Is different from Wikidata All article disambiguation pages All disambiguation pages PPIE (gene) 10450 56031 ENSG00000084072 ENSMUSG00000028651 Q9UNP9 Q9QZH3 NM_001195007 NM_006112 NM_203456 NM_203457 NM_001319293 NM_019489 NP_001181936 NP_001306222 NP_006103 NP_982281 NP_062362 Peptidylprolyl isomerase E (cyclophilin E) , also known as PPIE ,

112-421: Is highly correlated with cancer pathogenesis, but the specific mechanisms remain to be elucidated. PPIE (gene) has been shown to interact with CsA and MLL . Prolyl isomerase Prolyl isomerase (also known as peptidylprolyl isomerase or PPIase ) is an enzyme ( EC 5.2.1.8 ) found in both prokaryotes and eukaryotes that interconverts the cis and trans isomers of peptide bonds with

126-471: Is unique among the natural amino acids in having a relatively small difference in free energy between the cis configuration of its peptide bond and the more common trans form. The activation energy required to catalyse the isomerisation between cis and trans is relatively high: ~20kcal/mol ( cf. ~0kcal/mol for regular peptide bonds). Unlike regular peptide bonds, the X-prolyl peptide bond will not adopt

140-425: The native state include ribonuclease A , ribonuclease T1 , beta lactamase , cyclophilin , and some interleukins . Prolyl isomerase folding can be autocatalytic and therefore the speed of folding depends on reactant concentration. Parvulin and human cytosolic FKBP are thought to catalyze their own folding processes. Methods for identifying the presence of a rate-limiting proline isomerization process in

154-608: The amino acid proline . Proline has an unusually conformationally restrained peptide bond due to its cyclic structure with its side chain bonded to its secondary amine nitrogen. Most amino acids have a strong energetic preference for the trans peptide bond conformation due to steric hindrance , but proline's unusual structure stabilizes the cis form so that both isomers are populated under biologically relevant conditions. Proteins with prolyl isomerase activity include cyclophilin , FKBPs , and parvulin , although larger proteins can also contain prolyl isomerase domains . Proline

SECTION 10

#1732855334470

168-719: The close homology in the PPIase domain between PPIE and PPIA , PPIE may also be involved in the replication process of HIV . Moreover, PPIE helps to prevent infections by influenza A virus . As a cyclophilin, PPIE also binds the immunosuppressive drug CsA to form a CsA-cyclophilin complex, which then targets calcineurin to inhibit the signaling pathway for T-cell activation. In cardiac myogenic cells, cyclophilins have been observed to be activated by heat shock and hypoxia-reoxygenation as well as complex with heat shock proteins. Thus, cyclophilins may function in cardioprotection during ischemia-reperfusion injury. Currently, cyclophilin expression

182-428: The intended conformation spontaneously, thus, the process of cis-trans isomerization can be the rate-limiting step in the process of protein folding . Prolyl isomerases therefore function as protein folding chaperones . Cis peptide bonds N-terminal to proline residues are often located at the first residue of certain types of tight turns in the protein backbone. Proteins that contain structural cis -prolines in

196-485: Was first discovered using a chymotrypsin -based assay. The proteolytic enzyme chymotrypsin has a very high substrate specificity for the four-residue peptide Ala - Ala - Pro - Phe only when the proline peptide bond is in the trans state. Adding chymotrypsin to a solution containing a reporter peptide with this sequence results in the rapid cleavage of about 90% of the peptides, while those peptides with cis proline bonds - about 10% in aqueous solution - are cleaved at

#469530