Mob1p

Mob1p is a serine/threonine kinase protein that plays a crucial role in regulating cell cycle progression and maintaining cell polarity in the budding yeast Saccharomyces cerevisiae. It is a homolog of the mammalian phosphorylation-related proteins Mob1 and Mob2, which are involved in similar cellular processes.

Mob1p functions primarily as a regulatory subunit within the larger mitotic exit network (MEN) and the septation initiation network (SIN). These pathways are essential for the proper segregation of chromosomes and the completion of cytokinesis. Specifically, Mob1p interacts with and activates the kinase Cdc15, facilitating the transition from mitosis to the G1 phase. It also localizes to the spindle pole bodies and the bud neck during cell division, where it influences processes such as spindle positioning and bud emergence.

The activity and localization of Mob1p are tightly regulated through phosphorylation and interactions with other proteins. Disruption of MOB1 gene function results in defects in mitotic exit, abnormal cell division, and compromised cell polarity, emphasizing its importance in cell cycle integrity.

Research on Mob1p has provided insights into conserved mechanisms of cell division regulation across eukaryotes. Its role as a key component of kinase signaling pathways highlights its significance in ensuring accurate and efficient cell division, making it a focus of interest in studies of cell cycle control and related disorders.