Evidence for a G protein system in the tegumental brush border plasma membrane of Hymenolepis diminuta.
Guanine nucleotide-binding regulatory proteins (G proteins) mediate the transduction of signals from cell-surface receptors to intracellular effector enzymes. G protein alpha-subunits are routinely identified (and partially characterized) on the basis of their susceptibility to NAD(+)-dependent ADP-ribosylation NAD(+)-dependent ADP-ribosylation catalysed by cholera and/or pertussis toxins. Analysis of purified tegumental brush border plasma membrane from Hymenolepis diminuta by relevant methodologies has revealed the presence of a 42 kDa putative G protein alpha-subunit that is susceptible to ADP-ribosylation by both cholera and pertussis toxins. This polypeptide shows no definite resemblance to any of the four major mammalian G protein classes on the basis of M(r) and toxin-susceptibility. These results provide evidence for the existence of a tegumental G protein-linked signal transduction system in H. diminuta.
Department of Biological Sciences, University College of Wales, Aberystwyth, Dyfed, U.K.
J
J
Walker
J
J
Barrett
D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D019204:GTP-Binding Proteins / Q000032:analysis*; D006926:Hymenolepis / Q000737:chemistry* / Q000648:ultrastructure; D008871:Microvilli / Q000737:chemistry; D051381:Rats; D015398:Signal Transduction
D019204:GTP-Binding Proteins