TY - JOUR
T1 - Phosphorylation of p68 RNA helicase plays a role in platelet-derived growth factor-induced cell proliferation by up-regulating cyclin D1 and c-Myc expression
AU - Yang, Liuqing
AU - Lin, Chunru
AU - Zhao, Shumin
AU - Wang, Haizhen
AU - Liu, Zhi Ren
PY - 2007/6/8
Y1 - 2007/6/8
N2 - p68 RNA helicase is a protypical member of DEAD box family RNA helicase. The protein plays an important role in the cell developmental program and organ maturation. We demonstrated previously that, in response to growth factor platelet-derived growth factor (PDGF)-BB stimulation, p68 is phosphorylated at Tyr593, and the phosphorylation of p68 promotes epithelial- mesenchymal transition via promoting β-catenin nuclear translocation (Yang, L., Lin, C., and Liu, Z. R. (2006) Cell 127, 139-155). We show here that the tyrosine phosphorylation of p68 also mediates the effects of PDGF in stimulating cell proliferation. The phosphorylated p68 (referred to as phospho-p68) promotes cell proliferation by activating the transcription of cyclin D1 and c-Myc genes. We show that the ATPase/helicase activities of p68 are required for the activation of cyclin D1 transcription. The phospho-p68 participates in the complex assembled at the cyclin D1 and c-Myc promoters, which strongly suggests a direct role in transcriptional regulation. Furthermore, our data demonstrated that the phosphorylation of p68 at Tyr593 plays a role in mediating the autocrine loop effects of PDGF, suggesting an important role for p68 phosphorylation in cell proliferation.
AB - p68 RNA helicase is a protypical member of DEAD box family RNA helicase. The protein plays an important role in the cell developmental program and organ maturation. We demonstrated previously that, in response to growth factor platelet-derived growth factor (PDGF)-BB stimulation, p68 is phosphorylated at Tyr593, and the phosphorylation of p68 promotes epithelial- mesenchymal transition via promoting β-catenin nuclear translocation (Yang, L., Lin, C., and Liu, Z. R. (2006) Cell 127, 139-155). We show here that the tyrosine phosphorylation of p68 also mediates the effects of PDGF in stimulating cell proliferation. The phosphorylated p68 (referred to as phospho-p68) promotes cell proliferation by activating the transcription of cyclin D1 and c-Myc genes. We show that the ATPase/helicase activities of p68 are required for the activation of cyclin D1 transcription. The phospho-p68 participates in the complex assembled at the cyclin D1 and c-Myc promoters, which strongly suggests a direct role in transcriptional regulation. Furthermore, our data demonstrated that the phosphorylation of p68 at Tyr593 plays a role in mediating the autocrine loop effects of PDGF, suggesting an important role for p68 phosphorylation in cell proliferation.
UR - http://www.scopus.com/inward/record.url?scp=34447134154&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34447134154&partnerID=8YFLogxK
U2 - 10.1074/jbc.M610488200
DO - 10.1074/jbc.M610488200
M3 - Article
C2 - 17412694
AN - SCOPUS:34447134154
SN - 0021-9258
VL - 282
SP - 16811
EP - 16819
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 23
ER -