Regulation and function of G alpha protein subunits in Dictyostelium |
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Authors: | A Kumagai M Pupillo R Gundersen R Miake-Lye P N Devreotes R A Firtel |
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Institution: | Department of Biology, University of California, San Diego, La Jolla 92093. |
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Abstract: | We have examined the developmental regulation and function of two G alpha protein subunits, G alpha 1 and G alpha 2, from Dictyostelium. G alpha 1 is expressed in vegetative cells through aggregate stages while G alpha 2 is inducible by cAMP pulses and preferentially expressed in aggregation. Our results suggest that G alpha 2 encodes the G alpha protein subunit associated with the cAMP receptor and mediates all known receptor-activated intracellular signal transduction processes, including chemotaxis and gene regulation. G alpha 1 appears to function in both the cell cycle and development. Overexpression of G alpha 1 results in large, multinucleated cells that develop abnormally. The central role that these G alpha proteins play in signal transduction processes and in controlling Dictyostelium development is discussed. |
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