The repertoire of heterotrimeric G proteins and RGS proteins in Ciona intestinalis.
BACKGROUND
Heterotrimeric G proteins and regulators of G protein signaling (RGS) proteins are key downstream interacting partners in the G protein coupled receptor (GPCR) signaling pathway. The highly versatile GPCR transmembrane signaling system is a consequence of the coupling of a diverse set of receptors to downstream partners that include multiple subforms of G proteins and regulatory proteins including RGS proteins, among others. While the GPCR repertoire of Ciona intestinalis, representing the basal chordate is known, the repertoire of the heterotrimeric G proteins and RGS proteins is unknown.


RESULTS
In the present study, we performed an in-silico genome-wide search of C. intestinalis for its complement of G proteins and RGS proteins. The identification of several one-to-one orthologs of human G proteins at the levels of families, subfamilies and types and of homologs of the human RGS proteins suggests an evolutionarily conserved structure function relationship of the GPCR signaling mechanism in the chordates.


CONCLUSIONS
The C. intestinalis genome encodes a highly conserved, albeit, limited repertoire of the heterotrimeric G protein complexes with the size of subunit types comparable with that in lower eukaryotes.
Prasobh
R
R
Department of Biotechnology, Indian Institute of Technology Madras, Chennai, India.
Manoj
Narayanan
N
D000595:Amino Acid Sequence; D000818:Animals; D002938:Ciona intestinalis / Q000378:metabolism*; D020224:Expressed Sequence Tags; D016678:Genome; D020962:Heterotrimeric GTP-Binding Proteins / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D020710:RGS Proteins / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D020710:RGS Proteins; D020962:Heterotrimeric GTP-Binding Proteins