Nasser Rusan moved to the U.S. from Jordan in 1996. He graduated from the University of Massachusetts with a B.S. in molecular biology in 2000 and a Ph.D. in molecular and cellular biology in 2005. He conducted postdoctoral research at the University of North Carolina, Chapel Hill. In 2006, he received an American Cancer Society Postdoctoral fellowship, and in 2009 he received the University of North Carolina Postdoctoral Award for Research Excellence. Dr. Rusan joined the NHLBI in 2011 as an Earl Stadtman tenure-track Investigator. He is a member of the American Society for Cell Biology.
Dr. Rusan is interested in understanding the fundamentals of centrosome biogenesis. Specifically, he aims to uncover the mechanisms that control centrosome maturation. Through a genome-wide RNAi screen and from other published screens, he now has a large number of candidate genes that may play critical roles in centrosome maturation. The Rusan lab uses a variety of biochemical and cell biological methods, including high resolution live cell imaging, to perform structure/function studies on known and candidate centrosomal proteins in Drosophila.
Dr. Rusan is also interested in understanding the asymmetric activity of the two centrosomes during the asymmetric division of stem cells. For asymmetric divisions to proceed properly, stem cells must accomplish the following: 1) establish proper polarity, 2) build a functional mitotic spindle using centrosomes that steer and anchor it, and 3) properly align the spindle along a defined polarity axis using forces generated by astral microtubule (MT)-cortical interactions. If executed properly, stem cells divide asymmetrically to produce a differentiating daughter cell. However, defects in this process lead to missegregation of cell fate determinants. If both cells retain stem cell identity, this can, under certain circumstances, lead to tumorogenesis. Mutations in polarity genes (Lgl, Dlg, Scrib), cell fate determinants (Pros, Numb, Mira, Brat), and centrioles/centrosomes (sas-4, asl, aurora A, polo) can all lead to cell overgrowth and malignant transformation. Dr. Rusan combines the biochemical and imaging expertise of his lab to explore the dynamic features of asymmetric stem cell division, particularly the unique centrosome cycle that ensures proper mitotic spindle formation for asymmetric inheritance.
Dr. Rusan believes that the delineation of the Ca2+ signaling mechanisms that regulate the cell cycle is paramount to the understanding of developmental processes. Ca2+ ions function as intracellular second messengers that regulate a wide variety of cellular activities including fertilization, apoptosis, muscle contraction, lymphocyte activation, and cell cycle control and proliferation. Precise control of the cell cycle is critical throughout development, and Ca2+ functions in signal transduction pathways that regulate the cell cycle as early as fertilization. Dr. Rusan’s goal is to to understand the basic mechanisms by which Ca2+ signaling regulates the cell cycle and proliferation, particularly during development.
Together, Dr. Rusan’s lab studies these different aspects of the cell cycle to better understand how intracellular processes at the nanometer and micrometer scale can regulate tissue development and morphogenesis at the millimeter scale.