title: Ganglioside-mediated modulation of cell growth. Specific effects of GM3 and lyso-GM3 in tyrosine phosphorylation of the epidermal growth factor receptor.
abstract: Epidermal growth factor- (EGF) dependent tyrosine phosphorylation of the EGF receptor was inhibited by the exogenous addition of GM3 to a membrane preparation and to purified EGF receptor adsorbed to antireceptor-antibody-Sepharose (Bremer, E. G., Schlessinger, J., and Hakomori, S. (1986) J. Biol. Chem. 261, 2434-2440). A specific functional correlation between GM3 and EGF receptor function has been further assessed in this study, employing two variant clones of A431 cells showing completely different growth responses to EGF. The A1S clone showed EGF cell growth stimulation and contained GM3 whereas the A5I clone, whose growth was completely inhibited by EGF addition, lacked detectable GM3. Both the endogenous and EGF-dependent receptor tyrosine-kinase activities were low in the A1S clone and were only minimally inhibited by the exogenous addition of GM3. In contrast the EGF receptor kinase activity in A5I cells was much higher and was more strongly inhibited by GM3 than it was in A1S cells. The EGF receptor fraction prepared from A1S cells, eluted from an anti-EGF receptor antibody-Sepharose column, contained GM3, in contrast to the fraction prepared from A5I cells, which lacked detectable GM3. The receptor kinase activity in vitro was greatly influenced by detergent and ATP concentration. GM3 affected the receptor kinase in a biphasic manner, i.e. GM3 was inhibitory at a low concentration of detergent under a physiological concentration of ATP and stimulatory at a high concentration of detergent. In contrast lyso-GM3 displayed a monophasic inhibitory effect under a wide range of detergent concentrations. Lyso-CDH (lactosylsphingosine) had no detectable effect on the receptor kinase activity. The presence of a small quantity of lyso-GM3 in A431 cells was detected after DEAE-Sepharose chromatography followed by high performance liquid chromatography in a n-propanolyl alcohol-ammonia system. It is possible that de-N-fatty acylation of gangliosides could be an effective means to modulate EGF receptor function in membranes.
authors.affiliation: Department of Biochemical Oncology, Fred Hutchinson Cancer Research Center, University of Washington, Seattle 98104.
authors.forename: N
authors.initials: N
authors.lastname: Hanai
authors.forename: G A
authors.initials: GA
authors.lastname: Nores
authors.forename: C
authors.initials: C
authors.lastname: MacLeod
authors.forename: C R
authors.initials: CR
authors.lastname: Torres-Mendez
authors.forename: S
authors.initials: S
authors.lastname: Hakomori
mesh_terms: D000818:Animals; D002294:Carcinoma, Squamous Cell; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D004285:Dogs; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000187:drug effects / Q000378:metabolism*; D004912:Erythrocytes; D005679:G(M3) Ganglioside / Q000031:analogs & derivatives / Q000097:blood / Q000302:isolation & purification / Q000494:pharmacology*; D005732:Gangliosides / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D009154:Mutation; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005679:G(M3) Ganglioside; D005732:Gangliosides; C056605:lyso-G(M3) ganglioside; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases