Low temperature perception in plants: effects of cold on protein phosphorylation in cell-free extracts.
Activities of prevalent protein phosphatases decreased by nearly 95% and those of individual protein kinases were differentially reduced at low temperature. Inhibition of phosphatase activity at temperatures below 12 degrees C resulted in marked hyperphosphorylation of a 58-kDa protein (PP58). The temperature threshold for hyperphosphorylation of PP58 coincided with the known threshold for cold-induced calcium influx. Since calcium influx is triggered by several environmental stresses, we propose that the observed direct effects of cold on the phosphorylation of specific proteins enable cells to couple a shared calcium signal to a cold-specific transduction pathway.
Monroy
A F
AF
Department of Biology, McGill University, Montréal, Québec, Canada. amonroy@biol.lan.mcgill.ca
Labbé
E
E
Dhindsa
R S
RS
D000255:Adenosine Triphosphate / Q000378:metabolism; D047388:Casein Kinases; D002364:Caseins / Q000378:metabolism; D002474:Cell-Free System; D003080:Cold Temperature; D006657:Histones / Q000378:metabolism; D000455:Medicago sativa / Q000201:enzymology / Q000378:metabolism / Q000502:physiology*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D010766:Phosphorylation; D010936:Plant Extracts / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D006656:Protamine Kinase / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism
D002364:Caseins; D006657:Histones; D010936:Plant Extracts; D010940:Plant Proteins; D000255:Adenosine Triphosphate; D011494:Protein Kinases; D047388:Casein Kinases; D006656:Protamine Kinase; D010749:Phosphoprotein Phosphatases