Nogo-B is a new physiological substrate for MAPKAP-K2.
The neurite outgrowth inhibitor protein Nogo is one of 300 proteins that contain a reticulon homology domain, which is responsible for their association with the endoplasmic reticulum. Here we have found that the Nogo-B spliceform becomes phosphorylated at Ser107 in response to lipopolysaccharide in RAW264 macrophages or anisomycin in HeLa cells. The phosphorylation is prevented by SB 203580, an inhibitor of SAPK2a (stress-activated protein kinase 2a)/p38a and SAPK2b/p38b, and does not occur in embryonic fibroblasts generated from SAPK2a/p38a-deficient mice. Nogo-B is phosphorylated at Ser107 in vitro by MAPKAP-K2 [MAPK (mitogen-activated protein kinase)-activated protein kinase-2] or MAPKAP-K3, but not by other protein kinases that are known to be activated by SAPK2a/p38a. The anisomycin-induced phosphorylation of Ser107 in HeLa cells can be prevented by 'knockdown' of MAPKAP-K2 using siRNA (small interfering RNA). Taken together, our results identify Nogo-B as a new physiological substrate of MAPKAP-K2.
Rousseau
Simon
S
MRC Protein Phosphorylation Unit, Faculty of Life Sciences, University of Dundee, MSI/WTB Complex, Dow Street, Dundee DD1 5EH, Scotland, UK. s.rousseau@dundee.ac.uk
Peggie
Mark
M
Campbell
David G
DG
Nebreda
Angel R
AR
Cohen
Philip
P
D000595:Amino Acid Sequence; D000818:Animals; D045163:Antibodies, Phospho-Specific / Q000276:immunology; D002460:Cell Line; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides / Q000494:pharmacology; D051379:Mice; D008870:Microtubules / Q000378:metabolism; D048290:Mitogen-Activated Protein Kinase 11 / Q000378:metabolism; D048308:Mitogen-Activated Protein Kinase 14 / Q000378:metabolism; D008970:Molecular Weight; D009185:Myelin Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D000070798:Nogo Proteins; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D034622:RNA Interference; D013379:Substrate Specificity; D000099190:MAP-Kinase-Activated Kinase 2
D045163:Antibodies, Phospho-Specific; D047908:Intracellular Signaling Peptides and Proteins; D008070:Lipopolysaccharides; D048290:Mitogen-Activated Protein Kinase 11; D048308:Mitogen-Activated Protein Kinase 14; D009185:Myelin Proteins; D000070798:Nogo Proteins; D017346:Protein Serine-Threonine Kinases; D000099190:MAP-Kinase-Activated Kinase 2; C000603199:RTN4 protein, human; C000603201:Rtn4 protein, mouse; C098416:MAP-kinase-activated kinase 3