TY - JOUR
T1 - S6 phosphorylation-independent pathways regulate translation of 5′-terminal oligopyrimidine tract-containing mRNAs in differentiating hematopoietic cells
AU - Barth-Baus, Diane
AU - Stratton, Carl A.
AU - Parrott, Lou
AU - Myerson, Howard
AU - Meyuhas, Oded
AU - Templeton, Dennis J.
AU - Landreth, Gary E.
AU - Hensold, Jack O.
PY - 2002/5/1
Y1 - 2002/5/1
N2 - Synthesis of new ribosomes is an energy costly and thus highly regulated process. Ribosomal protein synthesis is controlled by regulating translation of the corresponding ribosomal protein (rp)mRNAs. In mammalian cells a 5′-terminal oligopyrimidine tract (TOP) is a conserved feature of these mRNAs that has been demonstrated to be essential for their translational regulation. Translation of TOP mRNAs has been proposed to be regulated by phosphorylation of ribosomal protein S6, which is a common effect of mitogenic stimulation of cells. However, as demonstrated here, S6 phosphorylation is not detectable in murine erythroleukemia (MEL) or other hematopoietic cells. The absence of S6 phosphorylation appears to be due to the action of a phosphatase that acts down-stream of S6 kinase, presumably on S6 itself. Despite the absence of changes in S6 phosphorylation, translation of TOP mRNAs is repressed during differentiation of MEL cells. These data demonstrate the existence of a mechanism for regulating S6 phosphorylation that is distinct from kinase activation, as well as the existence of mechanisms for regulating translation of TOP mRNAs that are independent of S6 phosphorylation.
AB - Synthesis of new ribosomes is an energy costly and thus highly regulated process. Ribosomal protein synthesis is controlled by regulating translation of the corresponding ribosomal protein (rp)mRNAs. In mammalian cells a 5′-terminal oligopyrimidine tract (TOP) is a conserved feature of these mRNAs that has been demonstrated to be essential for their translational regulation. Translation of TOP mRNAs has been proposed to be regulated by phosphorylation of ribosomal protein S6, which is a common effect of mitogenic stimulation of cells. However, as demonstrated here, S6 phosphorylation is not detectable in murine erythroleukemia (MEL) or other hematopoietic cells. The absence of S6 phosphorylation appears to be due to the action of a phosphatase that acts down-stream of S6 kinase, presumably on S6 itself. Despite the absence of changes in S6 phosphorylation, translation of TOP mRNAs is repressed during differentiation of MEL cells. These data demonstrate the existence of a mechanism for regulating S6 phosphorylation that is distinct from kinase activation, as well as the existence of mechanisms for regulating translation of TOP mRNAs that are independent of S6 phosphorylation.
UR - http://www.scopus.com/inward/record.url?scp=0036566786&partnerID=8YFLogxK
U2 - 10.1093/nar/30.9.1919
DO - 10.1093/nar/30.9.1919
M3 - ???researchoutput.researchoutputtypes.contributiontojournal.article???
C2 - 11972328
AN - SCOPUS:0036566786
SN - 0305-1048
VL - 30
SP - 1919
EP - 1928
JO - Nucleic Acids Research
JF - Nucleic Acids Research
IS - 9
ER -