English to Russian Medical Genetics

The cell cycle is divided into several phases. The majority of the cells in the body are in the quiescent G0 phase. Transition between the phases is governed by activation of protein kinases (cyclin-dependent kinase (CDK) family) mediated by their cyclin partners. A cell cycle inhibitory protein, retinoblastoma (pRB), is progressively phosphorylated and inactivated by cyclins in the G1 phase of the cell cycle leading to the transcriptional activation of genes required for S phase and DNA synthesis by the E2F family of transcription factors. CDK activity is kept in check by two families of CDK inhibitory proteins (CKIs): the p21 family and the p16 family.