Amino acids 367-376 of the Gs alpha subunit induce membrane association when fused to soluble amino-terminal deleted Gi1 alpha subunit.
AUTOR(ES)
Journot, L
RESUMO
Signal transduction GTP-binding proteins are tightly associated with plasma membrane. In the resting state, the anchorage of the alpha subunit could be indirect by means of the other beta gamma subunits or polydisperse multimers. In the activated state, although the alpha subunit is dissociated from other subunits, it is not released from the membrane and therefore is likely to contain information necessary to remain associated with the plasma membrane. Previous proteolytic experiments suggested that, in contrast to other G proteins alpha subunits, the C-terminal domain of Gs alpha (the G protein involved in adenylate cyclase stimulation) is essential for membrane association of the activated form. To better define the crucial residues involved in membrane attachment, we constructed chimeras between a soluble core and various parts of the Gs alpha C-terminal domain. We first deleted codons 2-6 of Gi1 alpha (the inhibitory G protein of the i1 subtype) to generate a soluble GTP-binding protein, delta N-Gi1 alpha. We then replaced the last 14 C-terminal codons of delta N-Gi1 alpha by different domains of the Gs alpha C terminus and looked for the membrane association of chimeric proteins after in vitro transcription, in vitro translation, and interaction with S49 cyc- membranes (obtained from a mutant cell line that does not express Gs alpha). Our results showed that addition of amino acids 367-376 of Gs alpha is sufficient to promote membrane association of the soluble N-terminal deleted Gi1 alpha.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=52866Documentos Relacionados
- The amino-terminal 200 amino acids of the plasma membrane Na+,K+-ATPase alpha subunit confer ouabain sensitivity on the sarcoplasmic reticulum Ca(2+)-ATPase.
- Regulation of catabolism of microinjected ribonuclease A requires the amino-terminal 20 amino acids.
- Isolation of an amino-terminal deleted recombinant ADP-ribosylation factor 1 in an activated nucleotide-free state.
- Amino-terminal truncations of the ribulose-bisphosphate carboxylase small subunit influence catalysis and subunit interactions.
- Crystal structure and association behaviour of the GluR2 amino-terminal domain