Biomembrane

Interest

Membrane protein insertion and topology. Packing of transmembrane fragments. Apoptosis. Viral membrane proteins. Pulmonary surfactant.

Projects

The purposes of our projects are to explore the mechanistic principles of membrane protein biogenesis, insertion, folding and assembly into lipid membranes, and to investigate the factors that determine membrane protein stability. Our interest focuses primarily on protein-protein interactions, which are essential for different aspects regarding membrane protein biology. These interactions are relevant for maintaining tertiary and quaternary structure and function of integral membrane protein complexes. In this context, we investigate the role of membrane-spanning domains, i.e. of transmembrane (TM) segments. These studies are performed using several membrane proteins as model systems for TM packing (glycophorin A), membrane insertion (leader peptidase), and topology (GFP and glycosylation assays). With these molecular tools we try to understand the structure and function of an array of membrane proteins, including the apoptotic Bcl-2 family proteins, pulmonary surfactant SP-C protein, and several channels and transporters.

The insertion into biological membranes of nascent protein chains depends on the protein-protein interactions established with the different components of the cellular machinery responsible for their insertion. Thus, we are analyzing the interacting network of membrane proteins throughout different insertion pathways using proteomic approaches.

Additionally, we are interested in viral membrane proteins from different viruses, including plant virus (movement proteins), animal enveloped virus, and viroporins.

Techniques

Packing of transmembrane fragments. Membrane protein targeting and insertion. Movement proteins of plant viruses. Pulmonary surfactant.

  • Heterologous expression and purification of membrane proteins in prokaryotic and eukaryotic systems.
  • Spectroscopic structural characterization (CD, Fluorescence).
  • Glycosylation mapping.
  • Molecular crosslinking.
  • Mass spectrometry (Protein identification, characterization, and quantitation).

Collaborations

  • Patricia Casino (University of Valencia)
  • Gunnar von Heijne (Stockholm University)
  • Victor Lorenz-Fonfria (University of Valencia)
  • Marc Marti-Renom (CNAG-CRG)
  • Jose L. Nieva (EHU-UPV)
  • Jesus Perez-Gil (Universidad Complutense Madrid)
  • Oliver Zerbe (University of Zurich)
  • Francisco N. Barrera (University of Tennessee-Knoxville)
  • Arne Elofsson (Stockholm University)
  • James C. Gumbart (Georgia Institute of Technology)