Cloning of a Drosophila melanogaster guanine nucleotide regulatory protein beta-subunit gene and characterization of its expression during development.

Abstract

A Drosophila melanogaster gene encoding a protein with >80% sequence identity to the .3 subunits of mammalian guanine nucleotide-binding regulatory proteins (G proteins) has been cloned. The gene, which was mapped to 13F on the X chromosome by in situ hybridization, was cloned from a Drosophila genomic library by using a bovine transducin (20,21) prompted us to search for homologous genes in Drosophila melanogaster. We chose Drosophila, a metazoan organism amenable to genetic manipulation, to better understand the functions of these ubiquitous proteins. Mutants with abnormalities in signal-transduction processes may result from mutations in G-protein genes. Potential phenotypes of Gprotein mutations include membrane polarization (22) and sensory (23) and learning (24)

A G-protein beta-subunit is essential for Dictyostelium development.

“…The D i c t y o s t e l i u r n G-protein f~-subunit shows a remarkable homology to the ~-subunits found in humans, D r o s o p h i l a , and C. e l e g a n s (Fong et al 1987;Gao et al 1987;Yarfitz et al 1988;van der Voorn et al 1990). Two common features of these homologous sequences have been noted previously, but the addition of the D i c t y os t e l i u r n sequence to the comparison markedly underscores these points.…”

“…Figure 2, in which we have arranged the sequences according to the internal repeat structure described previously (Fong et al 1986), compares the Dictyostelium f3 to human [3-2 (Fong et al 1987;Gao et al 1987), C. elegans f3 (van der Voorn et al 1990), and Drosophila ~ {Yarfitz et al 1988). …”

Isolation of cDNA of an auxin-regulated gene encoding a G protein beta subunit-like protein from tobacco BY-2 cells.

“…The arcA product comprises seven repetitive segments with an insertion of nonrepetitive sequence spanning t20-amino acid residues between the sixth and the last repeat units. This well-conserved motif was discovered in subtypes of G# from human (13)(14)(15)(16)(17) and later in a divergent group of organisms (18)(19)(20)(21). Currently, this growing family of protein includes two proteins involved in RNA splicing, PRP4 (for precursor RNA processing) (30) and PRP17 (27); proteins critical to cell-cycle regulation, CDC4 (29) and CDC20 (30); a protein involved in regulating Ras function, MSI1 (31); a protein that functions as a mediator of glucose repression, TUP1 (32,33); a protein essential for the maintenance of killer double-stranded RNA, MAK1l (maintenance of killer) (30) in yeast; as well as C12.3 cDNA in chicken (26), Cblp (Chlamydomonas ,B subunit-like protein) (25), and Enhancer of split, the product of a Drosophila neurogenic locus (34).…”

“…Therefore, the BY-2 cell line is particularly suitable for analyzing the cell cycle in plant cells. When we explored auxin-regulated genes upon auxin addition to tobacco BY-2 cells cultured without auxin for 3 days, we were able to isolate an auxin-regulated gene, which we designated arcA (for auxin-regulated gene from cultured cells).t Homology search in data bases revealed that arcA was homologous to genes that are structurally related to the ( subunit of heterotrimeric guanine nucleotide-binding regulatory proteins (G proteins) (13)(14)(15)(16)(17)(18)(19)(20)(21). In addition, we discuss the possibility that the arcA gene, as a member of the G protein ,B subunit (Gq) family, may have a role in inducing cell division.…”

Chemical excitation and inactivation in photoreceptors of the fly mutants trp and nss.

“…This missing protein is too large to be a G protein and its amino acid sequence does not resemble any known protein. The G protein of the fly eye, on the other hand, belongs to the G protein family (Blumenfeld et al, 1985;Bentrop and Paulsen, 1986;Paulsen and Bentrop, 1986;Devary et al, 1987;Yarfitz et al, 1988). The t~0 protein may be a component of a feedback loop which regulates the G protein activity or its interaction with the PLC.…”