Colorado State University

Our laboratory is focused on understanding the mechanisms regulating motor-based transport in cells, with a particular focus during mitosis. A fundamental and critical aspect of eukaryotic cells is their complex and well-defined internal organization. This high level of internal organization is achieved in large part by the well orchestrated motor-mediated delivery of various cargo to appropriate sites within the cell. The microtubule motors dynein and kinesin mediate the directional transport of cellular cargo (including the mitotic spindle) in the minus and plus end direction, respectively (i.e., toward the cell center, and the cell periphery, respectively). How these motors are regulated to carry out their respective functions is a central question in cell biology. We have recently identified a microtubule associated protein, She1, as a molecule with the ability to differentially affect the motility of dynein and kinesin. How this molecule achieves its motor specificity, and how this molecule is regulated within cells is unclear, and is one of the focuses of our laboratory. Techniques utilized by our lab include fluorescent microscopy (traditional wide-field, confocal, and total internal reflection fluorescence (TIRF) microscopy), genetics, biochemistry and various molecular biological approaches. For instance, using TIRF microscopy, we can watch single molecules of molecular motors walking along their respective tracks (see movies below). We expect that our findings will have implications for basic cellular biology, and also for understanding the pathogenesis of various disease states. For instance, aneuploidy (improper chromosome number) and tumor initiation correlate with defects in dynein mediated spindle positioning during cell division.