The DEAD-box RNA helicase Ded1p affects and accumulates in Saccharomyces cerevisiae P-bodies.
Recent results suggest that cytoplasmic mRNAs can form translationally repressed messenger ribonucleoprotein particles (mRNPs) capable of decapping and degradation, or accumulation into cytoplasmic processing bodies (P-bodies), which can function as sites of mRNA storage. The proteins that function in transitions between the translationally repressed mRNPs that accumulate in P-bodies and mRNPs engaged in translation are largely unknown. Herein, we demonstrate that the yeast translation initiation factor Ded1p can localize to P-bodies. Moreover, depletion of Ded1p leads to defects in P-body formation. Overexpression of Ded1p results in increased size and number of P-bodies and inhibition of growth in a manner partially suppressed by loss of Pat1p, Dhh1p, or Lsm1p. Mutations that inactivate the ATPase activity of Ded1p increase the overexpression growth inhibition of Ded1p and prevent Ded1p from localizing in P-bodies. Combined with earlier work showing Ded1p can have a positive effect on translation, these results suggest that Ded1p is a bifunctional protein that can affect both translation initiation and P-body formation.
Beckham
Carla
C
Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85721-0206, USA.
Hilliker
Angela
A
Cziko
Anne-Marie
AM
Noueiry
Amine
A
Ramaswami
Mani
M
Parker
Roy
R
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D005591:Chemical Fractionation; D022083:Cytoplasmic Structures / Q000201:enzymology*; D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004330:Drosophila; D017353:Gene Deletion; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006868:Hydrolysis; D014176:Protein Biosynthesis; D021381:Protein Transport; D020871:RNA Stability; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D000255:Adenosine Triphosphate; C492152:DED1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases