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Gα3 and protein kinase A represent cross‐talking pathways for gene expression in Dictyostelium discoideum
Author(s) -
Brandon Maureen A.,
Mahadeo Dana C.,
Podgorski Gregory J.
Publication year - 2002
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1046/j.1440-169x.2002.00658.x
Subject(s) - dictyostelium discoideum , protein kinase a , heterotrimeric g protein , dictyostelium , mutant , gene , biology , protein subunit , gene expression , signal transduction , microbiology and biotechnology , regulation of gene expression , phosphorylation , kinase , g protein , genetics
Heterotrimeric G proteins and protein kinase A (PKA) are regulators of development in Dictyostelium discoideum . It has been reported that disruption of the Dictyostelium Gα3 gene ( gα3 – ) blocks development and expression of several early development genes, characteristics that are reminiscent of mutants lacking the catalytic subunit of PKA ( pkac – ). The hypothesis that Gα3 and PKA signaling pathways may interact to control developmental gene expression was tested by comparing the regulation of seven genes expressed early in development in the wild‐type and in gα3 – and pkac – mutants, and comparing PKA activity in the wild‐type and in a gα3 – mutant. The expression patterns of six genes were affected similarly by the Gα3 and PKA mutations, while the expression of only one gene, the cAMP receptor 1 ( cAR1 ), differed between the mutants. PKA activity, measured by phosphorylation of the PKA‐specific substrate Kemptide, was higher in gα3 – cells than in wild‐type cells, suggesting that Gα3 normally exerts an inhibitory effect on PKA activity. Although some early development genes appear to require both Gα3 and PKA for expression, the differing response of cAR1 expression and the inhibitory effect of Gα3 on PKA activity suggest that Gα3 and PKA are members of interacting pathways controlling gene expression early in development.