Tag Archive for biochemistry

Hingorani, Biro ’09 Co-Author Article on Metal Toxin

Manju Hingorani, associate professor of molecular biology and biochemistry, is the co-author of “Mechanism of Cadmium-mediated Inhibition of Msh2-Msh6 Function in DNA Mismatch Repair,” published in Biochemistry, March 25, 2009. Three undergraduates from three countries worked on the project in the Hingorani Lab at Wesleyan. They include Francis Noah Biro ’09; Markus Wieland, an exchange student from University of Konstanz; and Karan Hingorani, Manju Hingorani’s nephew from St. Xaviers College in Mumbai who did volunteer work in the lab. The project focused on how the heavy metal toxin Cadmium (found in cigarette smoke, industrial pollution, batteries, etc.) causes DNA damage and blocks DNA repair, which promotes development of cancer.

Hingorani also co-authored the article “Mechanism of ATP-Driven PCNA Clamp Loading by S. cerevisiae RFC,” published in the Journal of Molecular Biology, March 13, 2009.

Mukerji Awarded NSF Funding for Her DNA Research

Ishita Mukerji, professor of molecular biology and biochemistry, uses a UV resonance Raman spectrometer to measure molecular vibrations. She examines the structure of DNA, to understand how protein modulation of the structure can lead to tumors and other diseases.

Ishita Mukerji, professor of molecular biology and biochemistry, uses a UV resonance Raman spectrometer to measure molecular vibrations. She examines the structure of DNA, to understand how protein modulation of the structure can lead to tumors and other diseases.

Errors in genomic DNA can lead to tumors and other diseases. By probing specific DNA structures, Ishita Mukerji hopes to gain an understanding of how such medical conditions can be prevented or possibly cured.

Mukerji, professor of molecular biology and biochemistry, studies how different proteins recognize and bind to DNA. Specifically, she examines four-stranded DNA structures, known as “Holliday junctions,” which are involved in DNA repair and recombination. These are different from the common, two-stranded DNA.

On April 1, Mukerji will receive a four-year grant worth $798,368 from the National Science Foundation (NSF) to fund her research project, “Structure and Function of Holliday Junctions Complexed With Proteins Probed by Fluorescence and UV Raman Spectroscopic Methods.”

“Both DNA repair and recombination are vital functions of the cell, which are needed to maintaining a stable and active genome,” Mukerji explains. “Our goal is to study the structure of the junctions and how that relates to their function.”

Holliday junction structures can be changed by protein binding. Mukerji will examine how these structures are altered by proteins that are known to be involved in repair and recombination and are known to bind to junctions.

“These studies address the overall mechanism of how DNA recombination occurs in the cell and the function of these proteins,” she says.

Chemistry graduate students Andrew Moreno and Jon King, MBB graduate student Yan Li and molecular biology and biochemistry major Olga Buzovetsky ’10, will assist Mukerji with the ongoing research.

Two different methods are used to study the DNA interactions: fluorescence spectroscopy and a laser technique, UV resonance Raman spectroscopy. By using the fluorescence method, the Mukerji group can examine and compare the structure of the junction and the protein-binding sites. By using the Raman technique, which examines molecular vibrations, they can probe protein and ion binding sites.

Wesleyan’s Chemistry Department and Molecular Biology and Biochemistry Department own several fluorescence spectrometers, and Mukerji has built her own, specialized UV resonance Raman spectrometer.

Most of the proposed research will be completed in Mukerji’s lab, although some computational studies will be done in collaboration with David Beveridge, the University Professor of the Sciences and mathematics, professor of chemistry. She is also collaborating with the Hingorani lab (MBB department) to study how proteins involved in mismatch repair and meiotic recombination bind to Holliday junctions. One set of experiments will be conducted at SUNY Buffalo.

The group will also examine how the protein-junction complex either facilitates or suppresses certain processes.

“One theory that we have is that the proteins we are studying suppress recombination as a means of preserving or maintaining the genome.” Mukerji says. “This is an idea that will be tested with the proposed experiments.”

Faculty Teach Elementary Students DNA, Natural History

Michael Singer, assistant professor of biology, taught a workshop on "Biodiversity in Connecticut and Beyond" during the Middletown Minds in Motion program March 21 at Snow Elementary School.

Michael Singer, assistant professor of biology, taught a workshop on "Biodiversity in Connecticut and Beyond" during the Middletown Minds in Motion program March 21 at Snow Elementary School. Singer taught participants about natural history and the biologically diverse animals that inhabit Connecticut ecosystems, focusing on insects, reptiles and amphibians.

Ishita Mukerji, professor of molecular biology and biochemistry, taught a workshop titled "Who Done It? A DNA Investigation."

Ishita Mukerji, professor of molecular biology and biochemistry, taught a workshop titled "Who Done It? A DNA Investigation."

During a “Who Done It? A DNA Investigation,” elementary school aged children sported white lab coats and became “detectives” hoping to solve a crime.

The students learned about DNA structure by isolating DNA from wheat germ and comparing DNA samples from a ‘crime scene’ with the DNA from five suspects. They learn how DNA forensics actually works – just like on the television show “CSI.”

Faculty, Students Attend Biophysical Society Meeting

A group of Wesleyan faculty, graduate and undergraduate students, along with three post-docs from the Molecular Biology and Biochemistry and Chemistry departments, attended the 53rd Annual Biophysical Society Meeting in Boston.

Several labs contributed posters including those run by David Beveridge, the University Professor of the Sciences and Mathematics, professor of chemistry; Irina Russu, professor of chemistry; Manju Hingorani, associate professor of molecular biology and biochemistry; Don Oliver, the Daniel Ayres Professor of Biology, chair and professor of molecular biology and biochemistry; and Ishita Mukerji, professor of molecular biology and biochemistry.

Noah Biro ’09 was a co-author on a poster contributed by Hingorani lab. David Snydacker ’09 and Maiko Kondo ’07 were co-authors on posters contributed by Mukerji lab.

Mukerji was a speaker on a panel titled “Transition from Postdoc to Faculty.”

Mukerji Awarded $780K from National Science Foundation

Ishita Mukerji.

Ishita Mukerji.

Ishita Mukerji, professor of molecular biology and biochemistry, received a $798,368 grant from the National Science Foundation for her project “Structure and Function of Holliday Junctions complexed With Proteins Probed by Fluorescence and UV Raman Spectroscopic Methods.”

The grant is a continuing grant which has been approved on scientific / technical merit for approximately four years. The grant will be awarded April 1.