Title: | Casein kinase II is required for cell cycle progression during G1 and G2/M in Saccharomyces cerevisiae |
Author(s): | Hanna DE; Rethinaswamy A; Glover CV; |
Address: | "Department of Biochemistry and Molecular Biology, University of Georgia, Athens 30602-7229, USA" |
ISSN/ISBN: | 0021-9258 (Print) 0021-9258 (Linking) |
Abstract: | "The catalytic subunit of Saccharomyces cerevisiae casein kinase II (Sc CKII) is encoded by the CKA1 and CKA2 genes, which together are essential for viability. Five independent temperature-sensitive alleles of the CKA2 gene were isolated and used to analyze the function of CKII during the cell cycle. Following a shift to the nonpermissive temperature, cka2ts strains arrested within a single cell cycle and exhibited a dual arrest phenotype consisting of 50% unbudded and 50% large-budded cells. The unbudded half of the arrested population contained a single nucleus and a single focus of microtubule staining, consistent with arrest in G1. Most of the large-budded fraction contained segregated chromatin and an extended spindle, indicative of arrest in anaphase, though a fraction contained an undivided nucleus with a short thick intranuclear spindle, indicative of arrest in G2 and/or metaphase. Flow cytometry of pheromone-synchronized cells confirmed that CKII is required in G1, at a point which must lie at or beyond Start but prior to DNA synthesis. Similar analysis of hydroxyurea-synchronized cells indicated that CKII is not required for completion of previously initiated DNA replication but confirmed that the enzyme is again required for cell cycle progression in G2 and/or mitosis. These results establish a role for CKII in regulation and/or execution of the eukaryotic cell cycle" |
Keywords: | Base Sequence Casein Kinase II *Cell Cycle Cell Nucleus/ultrastructure Cytoskeleton/ultrastructure Flow Cytometry Fungal Proteins/biosynthesis G1 Phase G2 Phase Hydroxyurea/pharmacology Mitosis Molecular Sequence Data Mutagenesis Protein Serine-Threonine; |
Notes: | "MedlineHanna, D E Rethinaswamy, A Glover, C V eng GM33237/GM/NIGMS NIH HHS/ Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, P.H.S. 1995/10/27 J Biol Chem. 1995 Oct 27; 270(43):25905-14. doi: 10.1074/jbc.270.43.25905" |