Membranes.

Gebhard Schertler was born in Dornbirn, Austria and studied Chemistry and Biochemistry at the University of Innsbruck, Austria. From 1984–1989 he did a PhD at the Max-Planck Institute for Biochemistry in Munich with Dieter Oesterhelt and Hartmut Michel. Major fields of study were in molecular biology, biophysics, and biochemistry of membrane proteins and membrane protein crystallisation. He switched to the field of G Protein-Coupled Receptors as a Research Associate in the Division of Structural Studies at the MRC Laboratory of Molecular Biology in 1989. He has moved to Switzerland and has been appointed as a full professor for structural biology at the ETH in Zurich in 2010. He is heading the Department of Biology and Chemistry and the Biomolecular Research Laboratory at the Paul Scherrer Institute in Switzerland. He is developing nano-diffraction methods with synchrotron radiation and free electron lasers. His laboratory is investigating receptor activation and the signalling complexes of GPCRs with a multidisciplinary approach. This is a time of critical increases in understanding membrane protein structures and their mechanisms in biology. As the first structures of membrane proteins determined by X-ray crystallography from rich natural sources, bovine rhodopsin, bovine aquaporin from eye lens and proteins from mammalian tissues, the advent of cloning and expression opened a broader horizon and first gave rise to predominantly prokaryotic membrane proteins expressed in a prokaryotic host. Eukaryotic proteins present greater challenges as their normal synthesis proceeds through cellular pathways inside the cell, processed in the endoplasmic reticulum and Golgi apparatus. Thus, as the number of membrane proteins is now increasing exponentially and primarily represented by prokaryotic species, the numbers of eukaryotic membrane proteins is steadily increasing, building toward the opportunities to understand targets of pharmacological significance. It emerges that different classes of receptors, transporters, pumps or channels often yield to crystallization using specialized techniques that serve to fix particular kinds of dynamical properties associated with transport or signaling. In this issue we sought to bring together a series of timely reviews that summarize several of the generally applicable technologies, alongside others that have so far gained special advantage for certain membrane protein classes.