<P> The MTOC reorients itself during signal transduction, primarily during wound repair or immune responses . The MTOC is relocalized to a position between the edge of the cell and the nucleus in cells like macrophages, fibroblasts, and endothelial cells . Organelles like the Golgi apparatus aid in the reorientation of the MTOC which can occur rapidly . Transduction signals cause microtubules to grow or contract, as well as cause the centrosome to become motile . The MTOC is located in a perinuclear position and contains the negative ends of microtubules while the positive ends grow rapidly towards the edge of the cell . The Golgi apparatus reorients along with the MTOC, and together cause the cell to seemingly send a polarized signal . </P> <P> In immune responses, upon interaction with a target cell in response to antigen - specific loaded antigen - presenting cells, immune cells, such as the T cells, natural killer cells, and cytotoxic T lymphocytes, localize their MTOCs near the contact zone between the immune cell and the target cell . For T cells, the T cell receptor signaling response causes the reorientation of the MTOC by microtubules shortening to bring the MTOC to the site of interaction of the T cell receptor . </P>

Microtubule organizing center that contains a pair of centrioles