Mode of interaction of the Gαo subunit of heterotrimeric G proteins with the GoLoco1 motif of Drosophila Pins is determined by guanine nucleotides.
Drosophila GoLoco motif-containing protein Pins is unusual in its highly efficient interaction with both GDP- and the GTP-loaded forms of the α-subunit of the heterotrimeric Go protein. We analysed the interactions of Gαo in its two nucleotide forms with GoLoco1-the first of the three GoLoco domains of Pins-and the possible structures of the resulting complexes, through combination of conventional fluorescence and FRET measurements as well as through molecular modelling. Our data suggest that the orientation of the GoLoco1 motif on Gαo significantly differs between the two nucleotide states of the latter. In other words, a rotation of the GoLoco1 peptide in respect with Gαo must accompany the nucleotide exchange in Gαo. The sterical hindrance requiring such a rotation probably contributes to the guanine nucleotide exchange inhibitor activity of GoLoco1 and Pins as a whole. Our data have important implications for the mechanisms of Pins regulation in the process of asymmetric cell divisions.
Department of Pharmacology and Toxicology, University of Lausanne, CH-1011, Switzerland.
Anne-Marie
AM
Lüchtenborg
Biotechnology Institute Thurgau, Kreuzlingen, CH-8280, Switzerland.
Vladimir
V
Purvanov
Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russian Federation.
Bogdan S
BS
Melnik
Department of Biology, University of Konstanz, 78457 Konstanz, Germany.
Simon
S
Becker
Department of Pharmacology and Toxicology, University of Lausanne, CH-1011, Switzerland School of Biomedicine, Far Eastern Federal University, Vladivostok 690922, Russian Federation vladimir.katanaev@unil.ch.
Vladimir L
VL
Katanaev
D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D060049:Asymmetric Cell Division / Q000235:genetics; D018797:Cell Cycle Proteins; D004330:Drosophila / Q000235:genetics; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000737:chemistry / Q000235:genetics*; D020730:Guanine Nucleotide Dissociation Inhibitors / Q000737:chemistry / Q000235:genetics*; D006150:Guanine Nucleotides / Q000235:genetics*; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry / Q000235:genetics*; D010455:Peptides / Q000737:chemistry / Q000235:genetics
D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D020730:Guanine Nucleotide Dissociation Inhibitors; D006150:Guanine Nucleotides; D010455:Peptides; C405164:Pins protein, Drosophila; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins
FRET; GoLoco; asymmetric cell division; heterotrimeric G proteins; nucleotide exchange