By Alison Aiken

This post highlights the work of Ryan Draker from Dr. Peter Cheung’s lab, published earlier this year in Nucleic Acids Research (PMID: 21245042) [Link to Paper].

In order for DNA to fit into cells, it gets coiled around octamers of small, positively charged proteins: the histones. Two each of histones H2A, H2B, H3 and H4 form the core of the nucleosome, around which DNA is coiled. Variant histones, which can differ significantly from core histones in their amino acid composition, can replace core histones in the nucleosome and are normally deposited in specific regions. A variant of H2A, H2A.Z, has been implicated in several cellular processes, including the regulation of transcription. Interestingly, H2A.Z can have either a positive or negative influence on gene transcription. This histone variant can be post-translationally modified by either acetylation or mono-ubiquitylation. Previous work by the Cheung lab has shown that H2A.Z is ubiquitylated by Ring1b, an E3 ligase that is part of the Polycomb Repressive Complex 1, and that mono-ubiquitylated H2A.Z is associated with transcriptionally inactive chromatin. The authors hypothesize, therefore, that the deubiquitylase(s) for H2A.Z would play an important role in the activation of transcription. Read the rest »

The James Lepock Memorial Student Research Symposium is set for June 2, 2011 at Princess Margaret Hospital. This annual event is organized in the style of a scientific conference and is an opportunity for MBP graduate students to showcase their research activities. It’s a great way to get exposure within our community and to gain experience in making poster and oral presentations.

Program and more information about the symposium

First Year Reps Jenny Hong and Jen Teichman are putting together this year’s Mentorship Program for incoming students, and we’re looking for Mentors among in-course students!

The Mentorship Program is meant to help new students with the transition from their undergraduate programs and to provide them with a go-to person in the department immediately upon arrival. As a mentor, you would be paired with a mentee who would then be given your contact information. At that point, the incoming student may want to ask you questions on rotations (for biology students), seminars, classes, getting involved in the department, etc.

If you’re interested in being a mentor for this year’s program, sign up here .

We need all the enthusiastic mentors we can get! Contact Jen (jennifer.teichman@utoronto.ca) or Jenny (jenny.hong@utoronto.ca) if you have any questions about the mentorship program.

Are you a 1st or 2nd year student preparing to give your first student seminar? Want to learn how to take your first seminar from good to great, perhaps even legendary? Your MBP GSU is organizing a few workshops for you on how to give great seminars. We’re aiming to run at least one workshop uptown and one workshop downtown. Please let us know what date and time are best for you by answering the appropriate polls below.

Of course, while workshops will give you valuable advice, nothing can replace knowing one’s talk inside and out, which can only be achieved by practice. For those without a lab group to whom they can present before their seminar, or for those who would simply like extra practice, we highly recommend booking a room, gathering a few peers, and asking them to provide constructive criticism.

If you need help booking a room or would like a few more pairs of critical eyes and ears, please contact anyone on the exec and we will gladly help you organize a practice talk.

Downtown: Best week for the workshop? April 4-8 April 11-15 April 18-22 Any of these weeks work for me None of these weeks work for me View Results  Loading ...	Downtown: Best Day of the Week? Monday Tuesday Wednesday Thursday Friday View Results  Loading ...
Sunnybrook: Best week for the workshop? April 4-8 April 11-15 April 18-22 Any of these weeks work for me None of these weeks work for me View Results  Loading ...	Sunnybrook: Best Day of the Week? Monday Tuesday Wednesday Thursday Friday View Results  Loading ...

(by Johnny Li)

Each month we will review/feature an article published by one of our very own MBP students in the biology and/or physics stream.

This article features the research of Aditya Murthy from Dr. Rama Khokha’s group [Link to Paper].

This research work focuses on fulminant hepatitis or acute liver failure, which is commonly induced by drugs such as paracetamol (acetaminophen) overdose and tetracycline, excessive alcohol intake, acute fatty liver during pregnancy, and viral hepatitis. Previous studies indicate that the establishment of fulminant hepatitis involves the cell death receptor Fas. Fas activation can both trigger hepatocyte apoptosis and hepatoprotective signals, dictating the survival or failure of the liver, and thus the organism. Engagement of this death receptor-mediated apoptosis in the liver is, however, a rather complex signaling network. Literature evidence suggests that tumor necrosis factor (TNF) signaling plays an important role in Fas-mediated fulminant hepatitis, though our knowledge on this is limited and incomplete. Additionally, the role of epidermal growth factor receptor (EGFR) signaling in acute hepatic stress is controversial. Read the rest »

Each month we will review/feature an article published by one of our very own MBP students in the biology and/or physics stream.

This article showcases the research of Angus Lau from Dr. Chuck Cunningham’s group [Link to Paper].

At the foundation of all biological molecules, carbon is indeed one of the most interesting and important nuclei that can be studied with MR. Unfortunately, carbon suffers from poor MR sensitivity: its MR-active ¹³C isotope is only 1% naturally abundant and its small magnetogyric ratio affords only a small population difference at ambient temperature. Dynamic nuclear polarization (DNP) is a technique that transfers spin alignment from electrons in free radicals to carbon nuclei. By increasing the ¹³C population difference in this way, MR signals can be enhanced by up to four orders of magnitude! The catch is that this non-equilibrium polarization decays irreversibly as the spins relax back to their Boltzmann configuration. Read the rest »

(by Natalie Nady)

Each month we will review/feature an article published by one of our very own MBP students in the biology and/or physics stream.

This article features research that was carried out in the labs of Dr. Emil Pai and Dr. Avi Chakrabartty and co-first authors were grad students Braden Sweeting and Qasim Khan from Biochemistry [Link to Paper].

This article talks about prions, a proteinaceous infectious particles which affect the brain or other neural tissue leading to various neurodegenerative diseases such as bovine spongiform encephalopathy (BSE, also known as “mad cow disease”) in cattle and Creutzfeldt–Jakob disease (CJD) in humans. All prion associated diseases are currently untreatable and universally fatal. Fortunately mammals vary in their prion disease susceptibility: hamsters and mice show relatively high susceptibility, whereas rabbits, horses, and dogs show low susceptibility. The mechanism of pathogenesis and the causes for varying susceptibility in mammals are not known. What is known is that in the native non-disease state of the protein, PrP, is alpha-helical. After infection, PrP is converted to predominantly beta-sheet form that aggregates into oligomers and amyloid fibrils. The transition between these secondary structure elements and oligomerization are not well defined. The authors used a combination of various biochemical techniques and structural biology to get a better understanding of how populated the beta-state is, its pathogenicity, and what drives the conversion between normal alpha and pathogenic beta-state. Read the rest »

Within the Department of Medical Biophysics we have a large internationally renowned faculty and many talented graduate students. To showcase our research we would like to feature monthly one or two articles published in a peer-reviewed journal by a fellow grad student. For the month of November 2010 we would like to draw your attention to two recent publications. Congratulations to all the authors on their great work!