Small Jab1‐containing subcomplex is regulated in an anchorage‐ and cell cycle‐dependent manner, which is abrogated by ras transformation

Jab1 interacts with a variety of cell cycle and signal transduction regulators to control cell proliferation, differentiation, and tumorigenesis. In this study, we employed a non‐denaturing gel electrophoresis method to separate different Jab1‐containing complexes, the COP9 signalosome complex and the small Jab1‐containing subcomplex. The formation of the small Jab1 complex was dependent on a low cell density and anchorage to a solid support, and enhanced during the early G1 phase of the cell cycle, which was abrogated in ras‐transformed cells. The small Jab1‐containing subcomplex may be a novel mediator of anchorage and cell–cell contact‐dependent signal transduction.