TY - JOUR
T1 - Stathmin is a Major Substrate for Mitogen‐activated Protein Kinase During Heat Shock and Chemical Stress in HeLa Cells
AU - Beretta, Laura
AU - Dubois, Marie‐Fraçoise ‐F
AU - Sobel, André
AU - Bensaude, Olivier
PY - 1995/1
Y1 - 1995/1
N2 - Stathmin is a ubiquitous, highly conserved 19‐kDa cytoplasmic protein whose expression and phosphorylation are regulated in relation to cell proliferation, differentiation or activation, in many biological systems. In this report, we show that stathmin undergoes major phosphorylation in HeLa cells submitted to heat or chemical stress. Heat‐shock‐induced stathmin phosphorylation was very rapid, as maximal incorporation of phosphate was observed at 5 min. Phosphorylation of stathmin might, therefore, occur as a very early step in the intracellular response to heat shock. The sites of phosphorylation of stathmin involved during the stress response were identified as mostly Ser25 and, to a lesser extent, Ser38. These sites are both followed by a proline residue, and known to be good substrates in vitro for mitogen‐activated protein kinase (MAP‐kinase) and p34cdc2 kinase, respectively. In lysates from heat‐shocked cells, an increased stathmin‐kinase activity, distinct from the histone‐H1‐kinase activity, was found to phosphorylate stathmin mostly on Ser25, the main site for MAP‐kinase in vitro. This stathmin‐kinase coeluted quantitatively with the stress‐activated MAP‐kinase from an FPLC MonoQ column. Furthermore, a stathmin kinase activity was precipitated from lysates of heat‐shocked HeLa cells by an anti‐(MAP‐kinase) serum. Together, these results indicate that the phosphorylation of stathmin by MAP‐kinase is likely to be a significant component of the signalling array controlling the cellular response to stress, and they further underline the general involvement of stathmin in intracellular signalling.
AB - Stathmin is a ubiquitous, highly conserved 19‐kDa cytoplasmic protein whose expression and phosphorylation are regulated in relation to cell proliferation, differentiation or activation, in many biological systems. In this report, we show that stathmin undergoes major phosphorylation in HeLa cells submitted to heat or chemical stress. Heat‐shock‐induced stathmin phosphorylation was very rapid, as maximal incorporation of phosphate was observed at 5 min. Phosphorylation of stathmin might, therefore, occur as a very early step in the intracellular response to heat shock. The sites of phosphorylation of stathmin involved during the stress response were identified as mostly Ser25 and, to a lesser extent, Ser38. These sites are both followed by a proline residue, and known to be good substrates in vitro for mitogen‐activated protein kinase (MAP‐kinase) and p34cdc2 kinase, respectively. In lysates from heat‐shocked cells, an increased stathmin‐kinase activity, distinct from the histone‐H1‐kinase activity, was found to phosphorylate stathmin mostly on Ser25, the main site for MAP‐kinase in vitro. This stathmin‐kinase coeluted quantitatively with the stress‐activated MAP‐kinase from an FPLC MonoQ column. Furthermore, a stathmin kinase activity was precipitated from lysates of heat‐shocked HeLa cells by an anti‐(MAP‐kinase) serum. Together, these results indicate that the phosphorylation of stathmin by MAP‐kinase is likely to be a significant component of the signalling array controlling the cellular response to stress, and they further underline the general involvement of stathmin in intracellular signalling.
KW - MAP‐kinase
KW - Stathmin
KW - heat shock
KW - protein phosphorylation
KW - signal transduction
UR - http://www.scopus.com/inward/record.url?scp=0028883292&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0028883292&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1995.tb20401.x
DO - 10.1111/j.1432-1033.1995.tb20401.x
M3 - Article
C2 - 7851413
AN - SCOPUS:0028883292
SN - 0014-2956
VL - 227
SP - 388
EP - 395
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
IS - 1-2
ER -