Microtubule Organizing Center - Signal Tranduction

Signal Tranduction

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, such as the Golgi apparatus, aid in the reorientation of the MTOC and can occur rapidly. Transduction signals cause microtubules to grow or contract, as well as 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.

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.