title: A critical step for JNK activation: isomerization by the prolyl isomerase Pin1.
abstract: c-Jun N-terminal kinase (JNK) is activated by dual phosphorylation of both threonine and tyrosine residues in the phosphorylation loop of the protein in response to several stress factors. However, the precise molecular mechanisms for activation after phosphorylation remain elusive. Here we show that Pin1, a peptidyl-prolyl isomerase, has a key role in the JNK1 activation process by modulating a phospho-Thr-Pro motif in the phosphorylation loop. Pin1 overexpression in human breast cancer cell lines correlates with increased JNK activity. In addition, small interfering RNA (siRNA) analyses showed that knockdown of Pin1 in a human breast cancer cell line decreased JNK1 activity. Pin1 associates with JNK1, and then catalyzes prolyl isomerization of the phospho-Thr-Pro motif in JNK1 from trans- to cis-conformation. Furthermore, Pin1 enhances the association of JNK1 with its substrates. As a result, Pin1(-/-) cells are defective in JNK activation and resistant to oxidative stress. These results provide novel insights that, following stress-induced phosphorylation of Thr in the Thr-Pro motif of JNK1, JNK1 associates with Pin1 and undergoes conformational changes to promote the binding of JNK1 to its substrates, resulting in cellular responses from extracellular signals.
authors.affiliation: Medical Proteomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Korea.
authors.forename: J E
authors.initials: JE
authors.lastname: Park
authors.forename: J A
authors.initials: JA
authors.lastname: Lee
authors.forename: S G
authors.initials: SG
authors.lastname: Park
authors.forename: D H
authors.initials: DH
authors.lastname: Lee
authors.forename: S J
authors.initials: SJ
authors.lastname: Kim
authors.forename: H-J
authors.initials: HJ
authors.lastname: Kim
authors.forename: C
authors.initials: C
authors.lastname: Uchida
authors.forename: T
authors.initials: T
authors.lastname: Uchida
authors.forename: B C
authors.initials: BC
authors.lastname: Park
authors.forename: S
authors.initials: S
authors.lastname: Cho
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000201:enzymology; D045744:Cell Line, Tumor; D004789:Enzyme Activation; D005260:Female; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D019169:Jurkat Cells; D051379:Mice; D018345:Mice, Knockout; D048055:Mitogen-Activated Protein Kinase 8 / Q000737:chemistry / Q000378:metabolism*; D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D018384:Oxidative Stress; D019696:Peptidylprolyl Isomerase / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D011392:Proline / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D011487:Protein Conformation; D059748:Proteolysis / Q000187:drug effects; D020860:Subtilisin / Q000494:pharmacology; D013912:Threonine / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*
chemical_list: D000072340:NIMA-Interacting Peptidylprolyl Isomerase; D013912:Threonine; D014443:Tyrosine; D011392:Proline; D048055:Mitogen-Activated Protein Kinase 8; D020860:Subtilisin; C000606846:PIN1 protein, human; D019696:Peptidylprolyl Isomerase; C000606850:Pin1 protein, mouse