Regulation Of Assembly Of Bipolar Myosin Ii Filaments

Myosin is a motor protein that has many different functions, including muscle contraction, cell transport, and cell adhesion. The current project focuses on non‐muscle myosin II B in Drosophila. Myosin is composed of heavy chains and light chains. There are two identical heavy chains that each contain an N‐terminal globular head region, neck region, and a C‐terminal long α‐helical tail region. There are also two types of light chains, the regulatory light chain and essential light chain. The phosphorylation state of the regulatory light chain regulates whether myosin is in an active or inactive position. In myosin's inactive position, it is believed that part of the tail region binds to the neck region. To understand the mechanism underlying myosin activation and inactivation, it is essential to pinpoint the site where the neck region binds to the tail region. We approach this question by expressing varying lengths of the tail region and assay neck region binding to these tail region fragments, thereby systematically narrowing down the location of binding on the primary structure of the tail region. To accomplish this, we must first coexpress the neck region with the light chains. So far, it has been confirmed that the heavy chain can be coexpressed with the light chains and form the desired trimeric complex. The information gained from this experiment will help us better understand the regulation of non‐muscle myosin II B.