Meet Levchenko
“Information Transduction Capacity of Noisy Biochemical Signaling Networks”
Andre Levchenko was born in the Soviet Union, and grew up in a small town in Siberia. He was then educated at the Moscow Institute for Physics and Technology (associated with numerous Nobel Prize winners), receiving BS and MS degrees in biophysics. He then moved with his family to the US and continued his studies at Columbia University, being among the first recipients of a doctoral degree in Biomedical Engineering. He simultaneously worked at Memorial Sloan-Kettering Cancer Center on problems of drug resistance in cancer. After getting the degree, Andre did post-doctoral work at Caltech, working with several groups, including David Baltimore’s, on problems in cellular signal transduction. In 2001, Andre came to Johns Hopkins, joining the BME department among the first School of Engineering appointees. He has been on the BME faculty ever since, pursuing theoretical and experimental analysis of cell decision making.
Seminar Abstract
“Information Transduction Capacity of Noisy Biochemical Signaling Networks”
Molecular noise restricts the ability of an individual cell to resolve input signals of different strengths and gather information about the external environment. Transmitting information through complex signaling networks with redundancies can overcome this limitation. We developed an integrative theoretical and experimental framework, based on the formalism of information theory, to quantitatively predict and measure the amount of information transduced by molecular and cellular networks. Analyzing tumor necrosis factor (TNF) signaling revealed that individual TNF signaling pathways transduce information sufficient for accurate binary decisions, and an upstream bottleneck limits the information gained via integration over multiple pathways. Negative feedback affecting this bottleneck could both alleviate and enhance its limiting effect, despite decreasing noise. Bottlenecks likewise constrain information attained by networks signaling through multiple genes or cells. In this talk, I will also touch on further applications of this formalism to problems in biological development and cell death.
