immunoblot analysis and ptx adp-ribosylation of the purified light sarcoplasmic reticulum ( lsr ) , heavy sarcoplasmic reticulum ( hsr ) and t-tubule subcellular fractions indicate the discrete presence of g proteins in lsr , an unambiguous labelling of the hsr fraction , while t-tubule membranes clearly appear very rich in a go-like protein , confirming the observed preferential immunocytochemical distribution of g protein subunits .
C0033684
protein
C0599220
protein subunits