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Research Abstracts Online
January 2009 - March 2010

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University of Minnesota Twin Cities
Medical School
Department of Neuroscience

PI: LiLian Yuan

Investigations Into Peptide Sequence Characteristics

Developing Improved miRNA Target Prediction Tools

Stress-induced bi-directional Modulation of Neuronal Sustained Activity in the Medial Prefrontal Cortex

These researchers are involved in three projects using MSI resources. The first concerns determining the binding or interacting sites of a protein, which are the peptide elements that play key roles in binding to or interacting with another protein. A practical difficulty in large-scale peptide screening efforts is the "exponential exploding” problem, that is, the number of possible peptide sequences grows exponentially with the length of the sequence. These researchers are taking an in silico approach to this problem, in which a Support Vector Machine Regression (SVR) method is adopted to quantitatively model the relationship between the peptide sequences and the binding intensities.  

The second project is an investigation into microRNAs (miRNAs), a class of newly discovered genes capable of post-transcriptionally regulating the expression of other genes (their "targets”), by binding to the non-coding regions of those genes, leading to cleavage of transcripts and/or repression of translation. Despite many efforts paid by several research groups in the past ~3 years, the mechanism of the miRNA targeting remains elusive. The group is attempting to elucidate this mechanism using a strategy where configurations for a dynamic programming-based scoring scheme are randomly created and summarized with supervised and unsupervised machine learning-based analysis methods, for the purpose of achieving accurate miRNA targeting criteria with much improved coverage than existing methods.

The third project involves the microcircutry in the neocortex, which responsible for information processing in the brain and is changed by experience. The researchers have found that deep-layer pyramidal neurons in medial prefrontal cortex (mPFC) experienced bouts of spontaneous resting membrane-potential bistability. Behavioral stress exerts strong, bi-directional influences on this neuronal activity. The researchers seek to understand signaling pathways that mediate the action of stress in mPFC.

Group Members

Tongbin Li, Faculty Collaborator
Marc Parent, Graduate Student
Rendong Yang, Collaborator
Liangsheng Zhang, Collaborator
Dihan Zhou, Collaborator