Anaphase specific auto‐cleavage of separase

Abstract

Sister-chromatid separation is triggered by a speci¢c proteolytic cleavage of chromosomal cohesins catalyzed by the endopeptidase separase. Prior to anaphase, separase is inhibited independently by a⁄nity binding to securin and by speci¢c inhibitory phosphorylation. Here we show that separase itself is also subjected to proteolytic cleavages at three adjacent sites. The cleavages are auto-catalyzed and occur speci¢cally at anaphase coincident with separase activation. The cleaved fragments remain associated with each other and are catalytically active. Mapping of the cleavage sites reveals that all three sites are conserved in vertebrates underlining a signi¢cant function for this regulation. ß 2002 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

t(8;21)(q22;q22) fusion proteins preferentially bind to duplicated AML1/RUNX1 DNA-binding sequences to differentially regulate gene expression

“…Further, we examined separase protein expression ( Figure 6C). Correlated to the change in mRNA level, both full-length and cleaved forms of separase protein 52,53 were also decreased after AML1-ETO expression at day 2 after tetracycline removal in U937T-AE cells. The tetracycline removal itself did not effect separase protein expression in the control U937T cells (Figure 6C right).…”

Role of cleavage by separase of the Rec8 kleisin subunit of cohesin during mammalian meiosis I

“…Proven separase substrates include Scc1 and separase itself in humans (Hauf et al, 2001;Waizenegger et al, 2002;Zou et al, 2002) and Scc1, Rec8 and Slk19 in yeast (Uhlmann et al, 1999;Buonomo et al, 2000;Tomonaga et al, 2000;Sullivan et al, 2001;Kitajima et al, 2003). The consensus recognition sequence is ExxR (the peptide bond after the Arg being cleaved) (Fig.…”

“…Separase prefers to cleave at R454, but mutation of this site (M2) revealed a cryptic secondary site elsewhere in the protein. Co-migration of aa 1-454 and aa 455-591 polypeptides (Uhlmann et al, 1999;Buonomo et al, 2000;Tomonaga et al, 2000;Hauf et al, 2001;Sullivan et al, 2001;Waizenegger et al, 2002;Zou et al, 2002;Kitajima et al, 2003) S1A). This assignment is consistent with the observation that the mobility of the smaller but not the larger cleavage fragment is reduced by Myc epitopes added to the C-terminus of Rec8 (Fig.…”

Critical Differences between Isoforms of Securin Reveal Mechanisms of Separase Regulation

“…3B). A key characteristic of activated human ESP1 is its autocleavage activity (12,34,35). Notably, both full-length ESP1 and the cleaved product (ESP1⌬) were able to bind PTTG1 (Fig.…”