Describe how both Gq alpha Go and betagamma subunits can act

Describe how both Gq alpha, Go and beta/gamma subunits can activate phospholipase C.

Solution

Guanine nucleotide binding proteins rae group of proteins that have the ability to bind GTP (guanosine triphosphate) and GDP (guanosine di phosphate). The G protein in the activation of phospholipase C remain attached to the GPCR ( g protein coupled receptor) in a hetero trimeric form that is has three subunits G alpha, G beta and G gamma.

G alpha and G beta subunit remain attached to the plasma membrane by lipid anchors. In the abscence of nay signal the GDP ( inactve form) remains attached to the alpha subunit of the trimeric form. thus the whole inactive GDP- G protein remains attached to the GPCR. these complex persists till any signalling molecule attaches itself to the GPCR, as soon as any signalling molecule attaches itself to the GPCR, the change in the conformation of the GPCR occurs which activates the G protein. in the activated G protein the GTP replaces the GDP at the alpha subunit.

the attachment of GTP dissociates the trimeric G protein into two subparts 1) GTP bound G alpha subunit 2) G beta-gamma dimer, bot of these parts but till remain attached to the plasma membrane but dissociates from the GPCR, thus they have the opportunity to interact with other membrane proteins.Whenever a G protein is active, both of its GTP-bound alpha subunit and its beta-gamma dimer can relay messages in the cell by interacting with other membrane proteins involved in signal transduction or activation of phospholipase C