Abstract 9603666 Tonks The phosphorylation of proteins on tyrosyl residues is an essential element in he control of many fundamental cellular processes including growth and proliferation, differentiation, cytoskeletal function and the cell cycle. At the present time there is a lot of progress in determinating the structure, regulation and function of protein tyrosine k8inases (PTKs) and protein tyrosine phosphatases (PTPs), the coordinated action of which governs the levels of cellular phosphotyrosine. This grant is to provide funds for the third meeting on Tyrosine phosphorylation and cellular signaling ,which will provide a format in which studies of PTK and PTPs will be integrated so that the scientists can see how their results contribute to the overall big picture. The sessions will be organized around physiological processes and cellular functions to provide a biological context. With the exception of 2 keynote addresses, all speakers will be selected from the submitted abstracts. This will encourage graduate students, postdocs and young independent investigators to present the talks. It shoud also facilitate the presentation of the most recent results. This meeting on tyrosine phosphorylation and cell signalling , palcae emphasis on the biological function of htese proteins. The format also encourages young scientists and new findings to be presented and discussed. The intent is to encourage cohesiveness and communication among scientists working on phosphorylation and cell signaling. ***