Rudhira/BCAS3 is a cytoskeletal protein that controls Cdc42 activation and directional cell migration during angiogenesis

Cell migration is a common cellular process in angiogenesis and tumor metastasis. Rudhira/BCAS3 (Breast Cancer Amplified Sequence 3) is a conserved protein expressed in the embryonic vasculature and malignant tumors. Here, we show for the first time that Rudhira plays an active role in directional cell migration. Rudhira depletion in endothelial cells inhibits Matrigel-induced tube formation and retards healing of wounded cell monolayers. We demonstrate that during wound healing, Rudhira rapidly re-localizes and promotes Cdc42 activation and recruitment to the leading edge of migrating cells. Rudhira deficient cells show impaired downstream signaling of Cdc42 leading to dramatic changes in actin organization and classic cell polarity defects such as loss of microtubule organizing center (MTOC) and Golgi re-orientation. Biochemical assays and co-localization studies show that Rudhira interacts with microtubules as well as intermediate filaments. Thus, Rudhira could control directional cell migration and angiogenesis by facilitating crosstalk between cytoskeletal elements. (C) 2012 Elsevier Inc. All rights reserved.