The Universe of GTP-binding proteins: un tema con variationi

Air date: Wednesday, March 25, 2009, 3:00:00 PM
Time displayed is Eastern Time, Washington DC Local
Category: Wednesday Afternoon Lectures

Description: GTP binding (G) proteins of the Ras superfamily cycle between a GDP-bound inactive and a GTP-bound active state. The switch-ON reaction involves the exchange of tightly bound GDP against GTP, while the switch-OFF mechanism involves the enzymatic cleavage of GTP to GDP. The switch function is tightly regulated since those reactions are intrinsically very slow and are stimulated through factors acting in trans. The first reaction is catalysed by guanine nucleotide exchange factors, GEFs, while the second is activated by GTPase-activating proteins called GAPs. The inability of certain of these proteins to be down-regulated or their unregulated activation leads to various forms of diseases including cancer.

A lot is known about the structural requirements for the switch function of Ras proteins, the GEF and the GAP reaction, their membrane recruitment and the interaction with effectors.

The basic features and mechanistic principles using Ras and G proteins, the structural basis of the molecular switch, how it is activated and how it interacts with downstream effectors, will be presented. Particular attention will be given to the GTPase reaction and its importance for disease formation such as cancer, Retinitis pigmentosa or Parkinson.

The NIH Director's Wednesday Afternoon Lecture Series includes weekly scientific talks by some of the top researchers in the biomedical sciences worldwide.

Author: Alfred Wittenhofer
Runtime: 00:58:32
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