For ClC transporters, breaking up is hard to do

Many ion channels and transporters exist as oligomers with each subunit containing a distinct transport pathway.  A classic example is the ClC family of chloride channels and transporters that are homodimeric with a pathway for chloride permeation or chloride/proton anti-port through each subunit.  Because of their dimer structure, they have come to be known as “double-barreled shotguns” for chloride movement across the membrane.

Since each subunit appears to possess the complete machinery required for transport, it is  often wondered whether ClCs need to be dimeric in order to carry out function.  In a study published last week in Nature, Brandeis researchers Janice Robertson, Ludmila Kolmakova-Partensky and Professor Christopher Miller answer this question.  By introducing two tryptophan mutations at the dimer interface, they designed a variant of a ClC transporter that could be purified and crystallized as an isolated monomer.  With this, they were able to determine that the monomer alone was fully capable of carrying out chloride and proton transport function.  These results show that the dimer is not required and that the monomer is the fundamental unit of transport in ClCs.  The question of why ClCs evolved as dimers remains a key question for understanding membrane protein structure.

2010 Beckman Scholars

active site of thymidylate kinase colored by conservation of residues between humans and Cryptosporidium parvumBrandeis was recently awarded a grant from the Arnold and Mabel Beckman Foundation through their Beckman Scholars Program. This grant will support two students each through two summers and one academic year of undergraduate research.

Philip Braunstein and Jessica Hutcheson have been named the 2010 Beckman Scholars.  Braunstein (class of 2012) is a Biochemistry major identifying parasite-selective inhibitors of pyrimidine biosynthesis in the Hedstrom laboratory.  Hutcheson (2011) is a Biochemistry/Neruoscience major investigating the molecular processes that determine memory in the Griffith laboratory.

Congratulations to the winners!

Formal test of the theory of a Universal Common Ancestor

In letter to Nature, Doug Theobald, Assistant Professor of Biochemistry, presents a formal test of the theory that evolution proceeds from a single common ancestor, using model selection theory.

From sequence to consequence: Petsko-Ringe lab celebration

From Sequence to Consequence: Celebrating 30 Years of Science with
Dagmar Ringe and Greg Petsko

June 18-19, 2010
8:30 a.m. – 5:00 p.m.
Shapiro Auditorium

On September 4, 1980, Drs. Dagmar Ringe and Greg Petsko entered into an official collaboration, and the scientific community has never been the same since.  Now, 30 years later, their joint lab at Brandeis University is putting together a symposium to celebrate their combined lifetimes of achievement.  This 2-day event features 20 speakers who either trained or collaborated with the lab, plus a dinner reception on Friday night.  Registration is now open to all members of the Brandeis community.  Details and registration can be found at  The registration code is scc30.

Dagmar and Greg

Petsko elected to APS

Greg Petsko, Gyula and Katica Tauber Professor of Biochemistry and Chemistry, has been elected to the American Philosophical Society.

Brandeis professor and postdoc alumni win Searle Scholars grants

One Brandeis professor and two of our former postdocs are among the 15 recipients of the competitive Searle Scholars awards for 2010. Nelson Lau, an assistant professor in the Biology Dept., won for his work on “Germline Genome Regulation by Piwi Proteins and Small RNAs”. Katie Henzler-Wildman is a former postdoc from the Kern lab in Biochemistry who now has a lab at Washington Univ. in St. Louis. Katie received a grant to study “The Role of Protein Dynamics in Multidrug Resistance Transport Activity”. David Biron, an alumnus of the Sengupta Lab who is now an assistant professor at U. Chicago, received a grant to study “Understanding Lethargus: The Sleep-Like Behavior of the Nematode C. Elegans“.

Congratulations to all the winners!

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