Abstract
Recent studies have demonstrated that G-protein-linked signal transduction pathways play a significant role in the developmental program of the simple eukaryotic organism Dictyostelium. We have reported previously the isolation of a G-protein β-subunit and present here a more complete analysis of this gene. Low-stringency Southern blots and RFLP mapping studies suggest that the β-subunit is a unique gene found on linkage group II. Its deduced amino acid sequence of 347 residues is ~60% identical to those of the human, Drosophila, and Caenorhabditis elegans β-subunits. The carboxy-terminal 300 residues are about 70% identical; the amino-terminal 50 residues are quite divergent, containing only 10 identities. At all stages of growth and development, a single 1.9-kb β-subunit mRNA is present at a high level, and a specific antibody detects a single 37-kD protein. We propose that G- protein heterotrimers are formed when this β-subunit couples with each of the eight distinct G-protein α-subunits that are transiently expressed during development. Targeted disruption of the β-subunit gene had no effect on the viability of haploid cells, but resulted in the inability of cells to aggregate.
Original language | English (US) |
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Pages (from-to) | 986-995 |
Number of pages | 10 |
Journal | Genes and Development |
Volume | 7 |
Issue number | 6 |
DOIs | |
State | Published - 1993 |
ASJC Scopus subject areas
- Genetics
- Developmental Biology