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Lecture

Nuclear Transport: Small GTPases and Cellular Switches

In course

BIO-207: Cellular and molecular biology II

This course is aimed to familiarize students with the 3D organization of a eukaryotic cell, its compartmentalization, how cellular compartments communicate together and how a cell communicates with its environment. The related molecular mechanisms will be ...

Description

This lecture covers the process of nuclear transport, focusing on the role of small GTPases as cellular switches. It explains how proteins with nuclear localization signals are delivered to the nucleus through the Ran-GTPase cycle. The instructor discusses the conformational changes of GTP-bound and GDP-bound states in small GTPases, emphasizing their role as key regulators in cellular signaling pathways.

Instructors (3)

Wouter Richard Karthaus

Romain Zufferey

Françoise Gisou van der Goot Grunberg

Gisou van der Goot is the Head of the Laboratory of Cell and Membrane Biology, and founding member of the Global Health Institute (GHI), School of Life Sciences, at the Swiss Federal Institute of Technology Lausanne/EPFL (Ecole Polytechnique Fédérale de Lausanne). She is currently Vice President for Responsible Transformation, in charge of reinforcing values such as inclusion and sustainability throughout the School’s campus. From 2014 to 2020, she was Dean of the School of Life Sciences. Before joining EPFL, she was Group Leader at the Faculty of Sciences of the University of Geneva (UNIGE) and subsequently Associate Professor at the Faculty of Medicine of the same university. She studied engineering at the Ecole Centrale de Paris, then did a PhD in Molecular Biophysics at the Nuclear Energy Research Center, Saclay, France, followed by a postdoc at the European Molecular Biology Laboratory (EMBL) in Heidelberg. She obtained an EMBO Young Investigator award in 2001, a Howard Hughes International Scholar award in 2005 and the Swiss Prix Marcel Benoist in 2009, the same year she was elected EMBO member (European Molecular Biology Organisation). She is a leader in the fields of molecular and cellular understanding of bacterial toxins, the organization of mammalian membranes and in organelles biology. Professor van der Goot is member of diverse scientific boards such as the Swiss National Science Foundation (SNF), the Conseil suisse de la science et de la technologie (CSST) and the European Research Council (ERC).

Official source

Ontological neighbourhood

Biology

Cell biology: Cell signaling

Related concepts (23)

GTPase

GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a protein domain common to many GTPases. GTPases function as molecular switches or timers in many fundamental cellular processes. Examples of these roles include: Signal transduction in response to activation of cell surface receptors, including transmembrane receptors such as those mediating taste, smell and vision.

Ras GTPase

Ras, from "Rat sarcoma virus", is a family of related proteins that are expressed in all animal cell lineages and organs. All Ras protein family members belong to a class of protein called small GTPase, and are involved in transmitting signals within cells (cellular signal transduction). Ras is the prototypical member of the Ras superfamily of proteins, which are all related in three-dimensional structure and regulate diverse cell behaviours.

G protein

G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their activity is regulated by factors that control their ability to bind to and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When they are bound to GTP, they are 'on', and, when they are bound to GDP, they are 'off'. G proteins belong to the larger group of enzymes called GTPases.

Guanine nucleotide exchange factor

Guanine nucleotide exchange factors (GEFs) are proteins or protein domains that activate monomeric GTPases by stimulating the release of guanosine diphosphate (GDP) to allow binding of guanosine triphosphate (GTP). A variety of unrelated structural domains have been shown to exhibit guanine nucleotide exchange activity. Some GEFs can activate multiple GTPases while others are specific to a single GTPase. Guanine nucleotide exchange factors (GEFs) are proteins or protein domains involved in the activation of small GTPases.

Nuclear localization sequence

A nuclear localization signal or sequence (NLS) is an amino acid sequence that 'tags' a protein for import into the cell nucleus by nuclear transport. Typically, this signal consists of one or more short sequences of positively charged lysines or arginines exposed on the protein surface. Different nuclear localized proteins may share the same NLS. An NLS has the opposite function of a nuclear export signal (NES), which targets proteins out of the nucleus. These types of NLSs can be further classified as either monopartite or bipartite.

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