Gs and Gq signalings regulate hPEM-2-induced cell responses in Neuro-2a cells.
Rho family GTPase-specific guanine nucleotide exchange factors of the Dbl family regulate a variety of cellular events including cytoskeletal arrangement, signal transduction, and gene expression through activation of Rho family GTPases. In this study, we show that hPEM-2 is a downstream effector of G(s) and G(q) signaling in Neuro-2a neuroblastoma cells. Co-expression with hPEM-2 and GTPase-deficient (constitutively active) mutants of Gαs (Gα(s)Q213L) or Gα(q) (Gα(q)Q209L), but not other GTPase-deficient mutants of Gα subunit and Gβγ subunits, activated serum response element (SRE)-dependent gene transcription, which is known to be induced by Rho family activation. Although a dominant negative mutant of Rac1 strongly blocks Gα(s)Q213L or Gα(q)Q209L/hPEM-2 activated SRE-dependent gene transcription, those of Cdc42 or RhoA are marginally affected. A PKA inhibitor, H-89, attenuated Gα(s)/hPEM-2-activated SRE-dependent gene transcription. And a dominant negative mutant of c-Src and an Src inhibitor attenuated Gα(q)Q209L/hPEM-2-activated SRE-dependent gene transcription. Experiments using hPEM-2 deletion mutants indicate that some regions of hPEM-2 play an important role in enhancing SRE activation by G(s) and G(q) signalings. These results reveal that G(s) and G(q) signalings regulate hPEM-2 functions through PKA and c-Src in Neuro-2a neuroblastoma cells, respectively.
Department of Biomolecular Science, Faculty of Engineering, Gifu University, Yanagido, Gifu 501-1193, Japan.
Rika
R
Nagae
Katsuya
K
Sato
Yuko
Y
Yasui
Yoshiko
Y
Banno
Takahiro
T
Nagase
Hiroshi
H
Ueda
D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D045744:Cell Line, Tumor; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D043802:GTP-Binding Protein alpha Subunits, Gq-G11 / Q000378:metabolism*; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D064067:Rho Guanine Nucleotide Exchange Factors; D014158:Transcription, Genetic; D019061:src-Family Kinases
C577403:Arhgef9 protein, mouse; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors; D011505:Protein-Tyrosine Kinases; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D017868:Cyclic AMP-Dependent Protein Kinases; D043802:GTP-Binding Protein alpha Subunits, Gq-G11; D019205:GTP-Binding Protein alpha Subunits, Gs