Subgroups

Subgroups

Bioenergetics

Please find below the program overview of the two minisymposia, which will be held on February 2, 2013, during the BPS Annual Meeting. The final schedule and titles for the talks will be available on the Subgroup’s website. We look forward to meeting you in Philadelphia, Pennsylvania for a stimulating gathering that explores exciting advancements in mitochondrial research.

Mitochondrial Calcium Signaling: New Insights after Molecular Identification of the Calcium Uniporter

With the cloning of the mitochondrial calcium uniporter in 2011 by the Mootha and Rizzuto groups, genetic approaches to manipulate the calcium uniport have become available and revealed intricate regulation of this channel. Meanwhile, the existence of other mitochondrial calcium transport mechanisms in a cell type-specific manner has gained research attention. The minisymposium will highlight the new molecular mechanisms and their physiological functions.

Organizers:
Shey-Shing Sheu & György Hajnóczky

Speakers:
Vamsi K. Mootha, Harvard Medical School, Massachusetts General Hospital
Rosario Rizzuto, University of Padova, Padua, Italy
György Hajnóczky, Thomas Jefferson University
Shey-Shing Sheu, Thomas Jefferson University
Brian O’Rourke, Johns Hopkins University
John Lederer, University of Maryland

Mitophagy and Mitochondrial Dynamics

In eukaryotic cells, mitochondria exist in a state of continuous remodeling and renewal modulated by fission, fusion and mitophagy. This minisymposium will focus on recent advances concerning the cellular, molecular and biophysical mechanisms underlying mitophagy and mitochondria dynamics. The relation of these events to cell death and mitochondria-associated disease will also be highlighted.

Organizers:
John J. Lemasters and Richard J. Youle

Speakers:
Heidi M. McBride, McGill University
Mitochondrial Dynamics and Quality Control

Hiromi Sesaki, Johns Hopkins University
Mitochondrial Dynamics in Neurodegeneration

TBA, NIH
Aging, Caloric Restriction and Mitochondrial Dynamics

John J. Lemasters, Medical University of South
Carolina, Initiators of Type 1 and 2 Mitophagy

Richard J. Youle, NIH, PINK1- and Parkin-mediated Mitophagy

György Hajnóczky & Jan Hoek, Co-Chairs, Bioenergetics Subgroup

IDP

Is Your Protein Intrinsically Disordered? This is the second article in a series designed to guide biophysicists interested in exploring whether disorder contributes to the function or regulation of their protein. Proteins that fail to crystalize, are prone to proteolysis, are posttranslationally modified, or have simple amino acid sequences may include intrinsically disordered regions. Identifying disordered regions can substantially aid your research! Experimental approaches have been developed specifically for these proteins. Disordered proteins can mediate functional mechanisms not available to stable, structured proteins. There are several easy ways to initially test for disorder in proteins:

Run prediction analysis of your protein sequence online (http://www.disprot.org/predictors.php)

Use limited (also called native-state) proteolysis: Disordered regions are proteolyzed at faster rates than structured regions. N-terminal sequencing and mass-spectroscopy can identify the remaining stable fragments [Kostyukova et al. (2000) Eur. J. Biochem. 267: 6470-6475].

Measure the CD spectrum of your protein: disordered regions have a high percentage of random coil [Uversky et al. (2011) JMR 24: 647-655].

While none of these methods are sufficient by themselves to confirm the presence of disorder in a protein, they are quick approaches that will help determine whether you should approach your protein as a disordered polypeptide. If you suspect you have disordered regions, then more complex but higher resolution techniques – such as NMR, small angle X-ray scattering, analytical ultracentrifugation, and hydrogen exchange/mass spectrometry – can refine the boundaries of disordered regions, detect conformational changes in response to ligand binding, and identify changes in protein structure/function in response to post-translational modification. These and other methods are described elsewhere in detail [Uversky & Dunker (2012) Analytical Chemistry 84: 2096-2104; Keppel et al. (2011) Biochemistry 50, 8722-8732]. In addition, removing disordered regions may allow you to crystallize a folded domain, whereas adding a binding partner may promote folding of disordered regions permitting complex crystallization.

Alla Kostyukova & Sarah Bondos, Councilors, IDP Subgroup

October 2012 Table of Contents