Wednesday, 20th June 2018
Cell Biology and Immunology
Functional interactions between MAPK, Galphaq and other regulatory proteins of G-protein signalling related pathways






Catalina Ribas










Research summary:






G protein coupled receptors (GPCR) mediate the action of different messengers which play an essential role in many cellular functions. These receptors regulate a highly interconnected network of biochemical pathways including control of the activity of different members of the family of MAPK (Mitogen-Activated Protein Kinases). Gq-coupled GPCR signalling is involved in cardiovascular physiopathology, glucose metabolism and proliferation/apoptosis. A number of cellular proteins have been reported to interact with the G protein subunit Galphaq including known effectors and other type of interactors that are scaffold molecules that organise and facilitate Gq signalling. There are other interactors named regulators which limit Galphaq signalling by enhancing the GAP activity of the G protein or by sequestering it and preventing effectors to interact. Although most Gq functions are tied to the activation of one or more effectors, to date there still are Gq-dependent processes for which no effector has yet been identified. Results obtained in our laboratory suggest a new functional interaction between Galphaq and PKCz which is related with the activation of the MAPK ERK5 that appears to play an important role in the development of cardiac hypertrophy. Thus, we have been described a previously unreported adaptor role for Galphaq. In this context, our overall objective is to further characterize this new functional interaction and determine its role in other pathologies where ERK5 may be involved, as well as in other cellular functions related to Gq-coupled GPCR and their possible modulation by regulatory/scaffold signalling proteins (GRKs, Ric8, RGS, EBP50). 


Relevant publications: