Chromosome Research

, Volume 9, Issue 2, pp 85–96

The structural maintenance of chromosomes (SMC) family of proteins in mammals

  • Alexander R. BallJr.
  • Kyoko Yokomori

DOI: 10.1023/A:1009287518015

Cite this article as:
Ball, A.R. & Yokomori, K. Chromosome Res (2001) 9: 85. doi:10.1023/A:1009287518015


Structural maintenance of chromosomes (SMC) family proteins play critical roles in chromosome structural changes. SMC proteins are known to be involved in two major chromosome structural organization events required for mitotic segregation of chromosomes: mitotic chromosome condensation and sister chromatid cohesion. In eukaryotes, two separate sets of SMC heterodimers form the cores of two distinct multiprotein complexes termed ‘condensin’ and ‘cohesin’, each specialized for condensation or cohesion, respectively. It is clear that both condensin and cohesin are conserved in mammals, including humans. The mammalian complexes demonstrate dynamic changes in intracellular distribution in a cell cycle-dependent manner. At any point in the cell cycle, the intracellular localization of the majority of mammalian cohesin and condensin appears to be complementary. Cohesin is associated with chromatin in interphase, while condensin is largely cytoplasmic. Similarly, in mitosis, cohesin is mostly excluded from chromosomes while condensin is distinctly bound to them. Cell cycle-dependent targeting of the two complexes appears to play a major role in regulating their cell cycle-specific activities, and how this redistribution is controlled is an area of active research. Finally, there is evidence that SMC proteins may be involved in DNA recombination and repair. This review focuses on what we have learned about SMC family proteins in humans and other mammalian species in comparison to those in lower eukaryotes. The authors present their own views with regard to some of the major outstanding questions surrounding the nature and functions of the SMC family of proteins.

chromosome structure cohesin condensin SMC proteins 

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Alexander R. BallJr.
  • Kyoko Yokomori

There are no affiliations available

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