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Studying Cell Cycle-regulated Gene Expression by Two Complementary Cell Synchronization Protocols
Published on: June 6, 2017
Cell cycle regulation of the mammalian CDK activator RINGO/Speedy A
Ana Dinarina1, Patricia G Santamaria, Angel R Nebreda
1CNIO (Spanish National Cancer Center), Madrid, Spain.
Abstract:
Cell cycle progression is regulated by cyclin-dependent kinases (CDKs), whose activation requires the binding of regulatory subunits named cyclins. RINGO/Speedy A is a mammalian protein that has no amino acid sequence homology with cyclins but can activate CDKs. Here we show that RINGO/Speedy A is a highly unstable protein whose expression and phosphorylation are periodically regulated during the cell cycle. RINGO/Speedy A is degraded by the proteasome and the process involves the ubiquitin ligase SCF(Skp2). Overexpression of a stabilized RINGO/Speedy A form results in the accumulation of high levels of RINGO/Speedy A at late stages of mitosis, which interfere with cytokinesis and chromosome decondensation. Our data show that tight regulation of RINGO/Speedy A is important for the somatic cell cycle.
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