The Arabidopsis homolog of Scc4/MAU2 is essential for embryogenesis

J Cell Sci. 2017 Mar 15;130(6):1051-1063. doi: 10.1242/jcs.196865. Epub 2017 Jan 30.


Factors regulating dynamics of chromatin structure have direct impact on expression of genetic information. Cohesin is a multi-subunit protein complex that is crucial for pairing sister chromatids during cell division, DNA repair and regulation of gene transcription and silencing. In non-plant species, cohesin is loaded on chromatin by the Scc2-Scc4 complex (also known as the NIBPL-MAU2 complex). Here, we identify the Arabidopsis homolog of Scc4, which we denote Arabidopsis thaliana (At)SCC4, and show that it forms a functional complex with AtSCC2, the homolog of Scc2. We demonstrate that AtSCC2 and AtSCC4 act in the same pathway, and that both proteins are indispensable for cell fate determination during early stages of embryo development. Mutant embryos lacking either of these proteins develop only up to the globular stage, and show the suspensor overproliferation phenotype preceded by ectopic auxin maxima distribution. We further establish a new assay to reveal the AtSCC4-dependent dynamics of cohesin loading on chromatin in vivo Our findings define the Scc2-Scc4 complex as an evolutionary conserved machinery controlling cohesin loading and chromatin structure maintenance, and provide new insight into the plant-specific role of this complex in controlling cell fate during embryogenesis.

Keywords: Arabidopsis; Auxin; Cohesin-loading complex; Embryogenesis; MAU2; NIBPL; Scc2; Scc4.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / cytology
  • Arabidopsis / embryology*
  • Arabidopsis / genetics
  • Arabidopsis / metabolism*
  • Arabidopsis Proteins / chemistry
  • Arabidopsis Proteins / metabolism*
  • Carrier Proteins / chemistry
  • Carrier Proteins / metabolism*
  • Cell Cycle Proteins / metabolism
  • Cell Lineage
  • Cell Nucleus / metabolism
  • Cell Proliferation
  • Chromatin / metabolism
  • Chromosomal Proteins, Non-Histone / metabolism
  • DNA, Bacterial / genetics
  • G1 Phase
  • Green Fluorescent Proteins / metabolism
  • Mutation / genetics
  • Phenotype
  • Plant Roots / cytology
  • Plant Roots / metabolism
  • Protein Binding
  • Protein Domains
  • Seeds / embryology
  • Seeds / metabolism
  • Sequence Homology, Amino Acid*


  • Arabidopsis Proteins
  • Carrier Proteins
  • Cell Cycle Proteins
  • Chromatin
  • Chromosomal Proteins, Non-Histone
  • DNA, Bacterial
  • SCC4 protein, Arabidopsis
  • T-DNA
  • cohesins
  • Green Fluorescent Proteins