[No authors listed]
The R7 regulator of G protein signaling family (R7-RGS) critically regulates nervous system development and function. Mice lacking all R7-RGS subtypes exhibit diverse neurological phenotypes, and humans bearing mutations in the retinal R7-RGS isoform RGS9-1 have vision deficits. Although each R7-RGS subtype forms heterotrimeric complexes with Gβ5 and R7-RGS-binding protein (R7BP) that regulate G protein-coupled receptor signaling by accelerating deactivation of Gi/o α-subunits, several neurological phenotypes of R7-RGS knock-out mice are not readily explained by dysregulated Gi/o signaling. Accordingly, we used tandem affinity purification and LC-MS/MS to search for novel proteins that interact with R7-RGS heterotrimers in the mouse brain. Among several proteins detected, we focused on Gα13 because it had not been linked to R7-RGS complexes before. Split-luciferase complementation assays indicated that Gα13 in its active or inactive state interacts with R7-RGS heterotrimers containing any R7-RGS isoform. LARG (leukemia-associated Rho guanine nucleotide exchange factor (GEF)), PDZ-RhoGEF, and p115RhoGEF augmented interaction between activated Gα13 and R7-RGS heterotrimers, indicating that these effector RhoGEFs can engage Gα13·R7-RGS complexes. Because Gα13/R7-RGS interaction required R7BP, we analyzed phenotypes of neuronal cell lines expressing RGS7 and Gβ5 with or without R7BP. We found that neurite retraction evoked by Gα12/13-dependent lysophosphatidic acid receptors was augmented in R7BP-expressing cells. R7BP expression blunted neurite formation evoked by serum starvation by signaling mechanisms involving Gα12/13 but not Gαi/o These findings provide the first evidence that R7-RGS heterotrimers interact with Gα13 to augment signaling pathways that regulate neurite morphogenesis. This mechanism expands the diversity of functions whereby R7-RGS complexes regulate critical aspects of nervous system development and function.
KEYWORDS: {{ getKeywords(articleDetailText.words) }}
Sample name | Organism | Experiment title | Sample type | Library instrument | Attributes | |||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
{{attr}} | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
{{ dataList.sampleTitle }} | {{ dataList.organism }} | {{ dataList.expermentTitle }} | {{ dataList.sampleType }} | {{ dataList.libraryInstrument }} | {{ showAttributeName(index,attr,dataList.attributes) }} |
{{ list.authorName }} {{ list.authorName }} |