ASSOCIATION OF MULTIPLE GTP-BINDING PROTEINS WITH THE PLANT CYTOSKELETON AND NUCLEAR MATRIX

Several types of GTP-binding proteins exist in plant cells. These incl ude the ras-related low-molecular-weight monomeric GTP-binding protein s and the multi-subunit group which more closely resembles members of the mammalian heterotrimeric G-protein family. Proteins belonging to b oth of these families are known to be involved in cell signalling even ts and have until recently been assumed to be associated predominantly with membranes. We have investigated the possibility that GTP-binding proteins in plants also can be associated with membrane-free carrot ( Daucus carota L.) cytoskeletons and nuclear matrices. Our results demo nstrate that several low-molecular-weight GTP-binding proteins, and at least one G-protein alpha-subunit homologue, are associated with thes e cellular compartments. (C) 1995 Academic Press, Inc.