Cell cycle regulation of c-Jun N-terminal kinase activity at the centrosomes.
The c-Jun N-terminal kinase (JNK), a subgroup of the mitogen-activated protein kinase (MAPK) family of serine/threonine kinases, has established functions in cell growth and apoptosis. While the mechanisms are unclear, JNK has also been also implicated in signaling pathways that initiate cell cycle checkpoints and cell cycle progression. By following the localization of active and inactive JNK during the cell cycle, we have found that the majority of cellular JNK is soluble and present in the cytoplasm and the nucleus. Interestingly, insoluble fractions of JNK are also localized in nuclear and cytoplasmic speckles, and to the centrosomes. While JNK is associated with the centrosome throughout the cell cycle, it is only active at the centrosome from S phase through anaphase. This novel localization of centrosomal JNK is a possible link between JNK-activating stimuli and centrosome or cell cycle events.
MacCorkle-Chosnek
R A
RA
Department of Immunology, Baylor College of Medicine, Houston, Texas 77030, USA.
VanHooser
A
A
Goodrich
D W
DW
Brinkley
B R
BR
Tan
T H
TH
D000818:Animals; D000918:Antibody Specificity; D002453:Cell Cycle / Q000502:physiology*; D018385:Centrosome / Q000201:enzymology*; D006367:HeLa Cells; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D008856:Microscopy, Fluorescence; D020928:Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism*; D011817:Rabbits; D015398:Signal Transduction; D012995:Solubility
D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases