THE SIGNAL MODULATOR PROTEIN-14-3-3 TS A TARGET OF SPHINGOSINE-DEPENDENT OR N,N-DIMETHYLSPHINGOSINE-DEPENDENT KINASE IN 3T3(A31) CELLS

Phosphorylation of a 28 kDa protein in 3T3(A31) cells upon addition of semi-purified kinase was induced only by sphingosine (Sph) or N,N-dim ethylsphingosine (DMS), but not by 17 other lipids tested. The 28 kDa protein, a major target of Sph- or DMS-dependent kinase, is now identi fied as 14-3-3 protein, which modulates a number of key protein kinase s involved in regulation of intracellular signaling (Aitken A, Trends Biochem Sci 20:95-97, 1995; Morrison D, Science 266:56-57, 1994). Thus , Sph and DMS modulate the function of a versatile modulator controlli ng a number of Signaling molecules. (C) 1995 Academic Press, Inc.