If You Can't Stand The Heat...
What's To Do?

It's an understatement to say that summers in Tucson are hot. However, people have found many ways to cope with the extreme climate of Southern Arizona. Finding a shady sanctuary, taking a dip in a pool or going inside an air conditioned building are just a few possibilities on how people can beat the heat. Plants, however, aren't as lucky. The way that plants handle the ever-rising global temperature is the focus of Dr. Elizabeth Vierling's research at the University of Arizona.

Dr. Vierling's laboratory works with the model plant organism Arabidopsis thaliana, focusing on the function of Heat Shock Proteins (HSPs). HSPs are proteins that come to the rescue when exposure to high temperatures causes other essential proteins to unfold, losing their ability to function in the cell. The first responders to this cellular stress are small Heat Shock Proteins (sHSPs) that stabilize the protein, like an EMT would stabilize an injured person until they can be fully treated. sHSPs don't need any energy to stabilize other proteins, but for the same reason they don't have the ability to fully repair them. However, other energy dependent HSPs act like the doctors of the cell, repairing damaged proteins by refolding them, which allows the proteins to regain their function.

Matthew Grimes, an undergraduate in Dr. Vierling's Laboratory, works with a protein that was found to interact with an sHSP in Arabidopsis by Dr. Eman Basha. This protein was identified as an elongation factor, acting as part of the machinery that helps to create proteins within the cell. The process of making new proteins is vital for the survival of any organism, so logically this elongation factor would require protection by HSPs. Matthew's research involves characterizing the elongation factor protein, and defining its interaction with sHSPs.

Even though looking at one type of protein in a single plant organism may seem like a very small application, the scope of the Vierling Laboratory's research is much larger than it appears. HSPs are not only found in plants, but in many other organisms, including humans. sHSPs are involved in many human diseases including Alzheimer's, Parkinson's, and Huntington's disease. So the survival of plants and the future of worldwide agriculture are not the only reason that HSPs are important. Serious human health concerns relate as well. But don't worry; when you can't stand the heat, HSPs will protect you.

The US Department of Agriculture and The Howard Hughes Medical Institute (52005889) funded Matthew's work.

 

Sleeping To Learn?

Ana Egurrola, a second year pre-physiology student at the University of Arizona, has spent the summer working with Dr. David Euston and Dr. Bruce McNaughton investigating the importance of sleep in memory consolidation.

Research conducted by the Neural Systems, Memory and Aging Division of Arizona Research Labs at the University of Arizona includes multi-electrode recordings of the rat prefrontal cortex and hippocampus. The prefrontal cortex is responsible for retrieval from long-term memory, while the hippocampus plays a role in the initial storage and retrieval of recently learned memories. Projects are underway to determine how these two regions contribute to the process of memory consolidation, the transfer of information from short-term to long-term memory.

Present research involves the comparison of brain cell firing patterns during behavior and sleep. Patterns of cell firings induced by an activity have been known to be replayed in the sleep immediately following that activity, a process called reactivation. This finding may give insight into the role the prefrontal cortex and hippocampus play in learning and creating new memories.

Recent findings support the idea that reactivation may be related to memory consolidation in that reactivation is only seen within the first two weeks of presenting a rat with a novel task. Experiments are being conducted to test these findings.

" If we understood this process better we may be able to enhance people's learning ability or help those affected by aging-related memory disorders" states Dr. David Euston.

Egurrola is a participant in the Undergraduate Biology Research Program, which allows students to take part in current research of their interest. Her research is funded by a grant from the Howard Hughes Medical Institute (52005889) to the University of Arizona and by a grant from the National Institute of Mental Health (MH46823).

 

The Chemical Blueprint

Ahmed Badran, a freshman at the University of Arizona, has worked with Dr. Indraneel Ghosh since he was a senior at Tucson High School. He started UBRP during the summer of 2007.

Ahmed has worked on a number of projects involving the design of biological sensors. His current research is focused on developing a new methodology for the specific detection of multiple sequences of DNA, the chemical blueprint for life. This methodology potentially could be used for early diagnosis of genetic diseases in humans, pathogenic organisms, and transgenic crops.

In this new DNA diagnostic approach, two important proteins are used: the Green Fluorescent Protein (GFP) and zinc fingers. GFP is a green-colored fluorescent protein found in a species of jellyfish. Zinc fingers are proteins that very selectively recognize a portion of the DNA blueprint. Upon mixing very specific combinations of these tailor-made proteins in a test-tube, a unique fluorescent signal is observed only when a specific target DNA is present. This allows one to "see" specific double-stranded target DNA that may cause cancer or may indicate the presence of a pathogen.

Ahmad hopes that his research can one day be used to advance human health. The UBRP portion of his funding comes from a grant to the University of Arizona from the Howard Hughes Medical Institute (52005889).