Article

The cAMP-dependent protein kinase signaling pathway is a key regulator of P body foci formation.

Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210, USA.
Molecular cell (impact factor: 14.61). 09/2011; 43(6):973-81. DOI:10.1016/j.molcel.2011.06.032
Source: PubMed

ABSTRACT In response to stress, eukaryotic cells accumulate mRNAs and proteins at discrete sites, or foci, in the cytoplasm. However, the mechanisms regulating foci formation, and the biological function of the larger ribonucleoprotein (RNP) assemblies, remain poorly understood. Here, we show that the cAMP-dependent protein kinase (PKA) in Saccharomyces cerevisiae is a key regulator of the assembly of processing bodies (P bodies), an RNP complex implicated in mRNA processing and translation. The data suggest that PKA specifically inhibits the formation of the larger P body aggregates by directly phosphorylating Pat1, a conserved constituent of these foci that functions as a scaffold during the assembly process. Finally, we present evidence indicating that P body foci are required for the long-term survival of stationary phase cells. This work therefore highlights the general relevance of RNP foci in quiescent cells, and provides a framework for the study of the many RNP assemblies that form in eukaryotic cells.

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Keywords

assembly process
 
cAMP-dependent protein kinase
 
conserved constituent
 
discrete sites
 
eukaryotic cells
 
general relevance
 
larger P body aggregates
 
larger ribonucleoprotein
 
long-term survival
 
mechanisms regulating foci formation
 
mRNA processing
 
mRNAs
 
P bodies
 
P body foci
 
phosphorylating Pat1
 
processing bodies
 
quiescent cells
 
RNP assemblies
 
RNP complex
 
stationary phase cells