Disease relevance of Ppib

• In the present studies we have examined expression of CypB in rat proximal tubules, which contributes to the increased renal sodium reabsorption in this model of hypertension [1].
• CypB is an endoplasmic reticulum-localized prolyl-isomerase that interacts with elongation initiation factor 2-beta, an important regulator of protein translation and a central component of the endoplasmic reticulum stress response to hypoxia or ATP depletion [1].

High impact information on Ppib

• These results indicate that s-cyclophilin is a retained component of an intracellular organelle and that it may accumulate in specialized portions of the ER, and possibly in calciosomes [2].
• Because of its conserved structure, widespread distribution, and abundance s-cyclophilin may be a useful marker to study the biogenesis and distribution of ER subcompartments [2].
• Cyclophilins (cyclosporin A-binding proteins) are conserved, ubiquitous, and abundant proteins that accelerate the isomerization of XaaPro peptide bonds and the refolding of proteins in vitro. s-Cyclophilin is a member of the cyclophilin family with unique NH2- and COOH-terminal extensions, and with a signal sequence [2].
• The exogenous addition of CypB potentiated the 3H-thymidine incorporation of PRL-dependent cell lines up to 18-fold [3].
• CypB is a peptidyl prolyl isomerase (PPI) found in the endoplasmic reticulum, extracellular space, and nucleus [3].

Biological context of Ppib

• In view of evidence linking CypB to the regulation of elongation initiation factor-2, the upregulation of CypB may result from metabolic stress [1].
• Role of cyclophilin B in prolactin signal transduction and nuclear retrotranslocation [3].

Anatomical context of Ppib

• Further, CypB expression is also higher in a proximal tubule cell line derived from SHR compared with a similar line derived from Wistar-Kyoto rats, indicating that this difference is genetically determined [1].
• Using a novel rat model, this study assessed expression of cytochrome P450 mono-oxygenases (Cyps), glutathione S-transferases (GSTs) and uridine diphosphoglucuronosyl transferase (UGT) in intestinal epithelium during sequential stages of regeneration [4].

Other interactions of Ppib

• Induction of SNAP-25 accumulation occurred without an increase in its synthesis, and induction of cyclophilin B occurred without an increase in its messenger RNA accumulation, suggesting that accumulation may be caused by stabilization of the proteins [5].
• The inflammatory cytokine tumour necrosis factor-alpha up-regulated IP-10 and MCP-1 mRNA expression (10- and four-fold, respectively), but had no effect on cyclophilin B mRNA levels [6].

Analytical, diagnostic and therapeutic context of Ppib

• We report the molecular characterization of rat cyclophilin B (CypB) and demonstrate, through sequence analysis and an allele-specific polymerase chain reaction primer assay, that CypB but not Cy-LP is expressed in rat kidney [1].
• Western blot multiplexing with CypB was possible for all targets [7].

References