High impact information on SMC2

• Cnd1, Cnd2, and Cnd3, three non-SMC subunits showing a high degree of sequence conservation to frog subunits, are essential for viability, and their gene disruption leads to a phenotype indistinguishable from that observed in cut3-477 and cut14-208, known mutations in SMC4 and SMC2-like subunits [1].
• We show that the Trf4p associates physically with both Smclp and Smc2p, the S. cerevisiae homologs of Xenopus proteins that are required for mitotic chromosome condensation in vitro [2].
• We characterized the SMC2 (structural maintenance of chromosomes) gene that encodes a new Saccharomyces cerevisiae member of the growing family of SMC proteins [3].
• SMC2, a Saccharomyces cerevisiae gene essential for chromosome segregation and condensation, defines a subgroup within the SMC family [3].
• The Smc2p molecules are able to form complexes in vivo both with Smc1p and with themselves, suggesting that they can assemble into a multimeric structure [3].

Biological context of SMC2

• Both SMC2 and SMC4 are essential for chromosome transmission in anaphase [4].
• In vivo localization of Smc4p fused to green fluorescent protein showed that, unexpectedly, in S. cerevisiae the condensin complex concentrates in the rDNA region at the G2/M phase of the cell cycle. rDNA segregation in mitosis is delayed and/or stalled in smc2 and smc4 mutants, compared with separation of pericentromeric and distal arm regions [4].
• A second, highly homologous SMC2 gene, AtCAPE-2, was identified by the Arabidopsis genome project [5].
• SMC2 gene expression in Arabidopsis was correlated with the mitotic activity of tissues, with high level expression observed in meristematic cells [5].
• High mole ratios of Smc2/4 to plasmid promote a geometric change in circular DNA that can be trapped as knots by type II topoisomerases but not as supercoils by a type I topoisomerase [6].

Associations of SMC2 with chemical compounds

• Smc2/4 binds both linearized and circular plasmids, and the binding appears to be independent of adenylate nucleotide [6].

Other interactions of SMC2

• Overexpression of SMC2, a gene necessary for chromosome condensation, and a homologue of the XCAP-E condensin, does not suppress brn1, pointing to functional specialization of components of the condensin complex [7].

Analytical, diagnostic and therapeutic context of SMC2

• Genetic crosses were employed to examine the consequences of reduced SMC2 levels [5].
• Binding titration analyses reveal that two Smc2/4-DNA-bound states exist, one disrupted by and one resistant to salt challenge [6].

References