Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P05412 (c-Jun)
 11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

v-crk is an oncogene identified originally in CT10 chicken tumor virus. C3G, a guanine nucleotide exchange factor (GEF) for Rap1 and R-Ras, is postulated to transduce the oncogenic signal of v-Crk to c-Jun kinase (JNK). We have found that R-Ras, but not Rap1, mediates JNK activation by v-Crk in 293T and NIH 3T3 cells. Constitutively activated R-Ras, R-Ras(Val-38), but not Rap1(Val-12), activated JNK, as did the constitutively active H-Ras(Val-12) or Rac1(Val-12). v-Crk activation of JNK was inhibited by a dominant-negative mutant of R-Ras, R-Ras(Asn-43). JNK activation by R-Ras(Val-38) was inhibited by a dominant-negative mutant of mixed lineage kinase 3. Among six GEFs for Ras-family G proteins, mSos1, Ras-GRF, C3G, CalDAG-GEFI, Ras-GRP/CalDAG-GEFII, and Epac/cAMP-GEFI, GEFs for either H-Ras or R-Ras activated JNK and c-Jun-dependent transcription. CalDAG-GEFI and Epac/cAMP-GEFI, both of which are GEFs specific for Rap1, did not activate JNK or c-Jun-dependent transcription. These results demonstrate that R-Ras, but not Rap1, is the downstream effector of C3G to stimulate JNK. Finally, we found that expression of the dominant-negative R-Ras mutant induced flat reversion of NIH 3T3 cells transformed by v-Crk, suggesting that R-Ras-dependent JNK activation is critical for the transformation by v-Crk.
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PMID:Crk activation of JNK via C3G and R-Ras. 1077 59