The fate of metaphase kinetochores is weighed in the balance of SUMOylation during S phase
CELL CYCLE
Authors: Mukhopadhyay, Debaditya; Dasso, Mary
Abstract
Genetic evidence suggests that conjugation of Small Ubiquitin-like Modifier proteins (SUMOs) plays an important role in kinetochore function, although the mechanism underlying these observations are poorly defined. We found that depletion of the SUMO protease SENP6 from HeLa cells causes chromosome misalignment, prolonged mitotic arrest and chromosome missegregation. Many inner kinetochore proteins (IKPs) were mis-localized in SENP6-depleted cells. This gross mislocalization of IKPs is due to proteolytic degradation of CENP-I and CENP-H via the SUMO targeted Ubiquitin Ligase (STUbL) pathway. Our findings show that SENP6 is a key regulator of inner kinetochore assembly that antagonizes the cellular STUbL pathway to protect IKPs from degradation during S phase. Here, we will briefly review the implications of our findings and present new data on how SUMOylation during S phase can control chromosome alignment in the subsequent metaphase.
Perspective on Multi-Target Antiplatelet Therapies: High Content Phenotypic Screening as an Unbiased Source of Novel Polypharmacological Strategies
MINI-REVIEWS IN MEDICINAL CHEMISTRY
Authors: Landre, Vivien; Amelio, Ivano; Barlev, Nick A.; Knight, Richard A.; Lisitsa, Andrey; Melino, Gerry; Antonov, Alexey V.
Abstract
Platelets play an important role in cardiovascular thrombosis as well as in many other pathological conditions such as inflammation, atherosclerosis and cancer. While multi-target strategies to treat complex diseases are gaining considerable attention, current development of antiplatelet therapies is mostly oriented towards several single targets, arising from our present understanding of the regulation of platelet activation. Limited efforts to develop multi-target agents or multidrug therapies are mostly due to a lack of a systematic basis to define target combinations with synergistic effects. Here we discuss the perspective to use high content phenotypic screening of in vitro models as a potential source for inference of synergetic multi-target strategies to control platelet activation.