3.4.22.49 evolution in-depth bioinformatical analysis of separase and generation of structural models of the two conserved domains that comprise the C-terminal region: a caspase-like domain and a putative death domain. This analysis provides insights into substrate recognition and identifies potential sites of protein-protein interactions. Both the death domain and caspase-like domain are well-conserved in separases, which suggests an evolutionary pressure to keep these two domains together, perhaps to enable separase activity and/or provide stability -, 755059 3.4.22.49 evolution in-depth bioinformatical analysis of separase and generation of structural models of the two conserved domains that comprise the C-terminal region: a caspase-like domain and a putative death domain. This analysis provides insights into substrate recognition and identifis potential sites of protein-protein interactions. Both the death domain and caspase-like domain are well-conserved in separases, which suggests an evolutionary pressure to keep these two domains together, perhaps to enable separase activity and/or provide stability 755059 3.4.22.49 evolution separases belong to CD clan of cysteine proteases. Unlike other members of this clan, separases are large multidomain proteins with more than 1000 amino acid residues. Mode of action in vivo and mechanistic differences in mitosis between organisms, overview 718194 3.4.22.49 evolution separases belong to CD clan of cysteine proteases. Unlike other members of this clan, separases are large multidomain proteins with more than 1000 amino acid residues. The catalytic domain of Arabidopsis separase exhibits 31 and 32% identity to the corresponding domains of human and budding yeast homologues, respectively, while the identity exceeds 50% within plant kingdom showing that the proteolytic domain of separases is the most conserved one. The sequence identity drops dramatically for the N-termini of separases. For example, the identity of the first 600 amino acid residues between Arabidopsis and Vitis vinifera separases does not exceed 39%, and it is only 30% between Arabidopsis and rice. Mode of action in vivo and mechanistic differences in mitosis between organisms, overview 718194 3.4.22.49 evolution separases belong to CD clan of cysteine proteases. Unlike other members of this clan, separases are large multidomain proteins with more than 1000 amino acid residues. The catalytic domain of Arabidopsis thaliana separase exhibits 31 and 32% identity to the corresponding domains of human and budding yeast homologues, respectively. The sequence identity drops dramatically for the N-termini of separases. Mode of action in vivo and mechanistic differences in mitosis between organisms, overview 718194 3.4.22.49 evolution separases belong to CD clan of cysteine proteases. Unlike other members of this clan, separases are large multidomain proteins with more than 1000 amino acid residues. The sequence identity exceeds 50% within plant kingdom showing that the proteolytic domain of separases is the most conserved one. The sequence identity drops dramatically for the N-termini of separases. For example, the identity of the first 600 amino acid residues between Arabidopsis thaliana and Oryza sativa is only 30%. Mode of action in vivo and mechanistic differences in mitosis between organisms, overview 718194 3.4.22.49 evolution separases belong to CD clan of cysteine proteases. Unlike other members of this clan, separases are large multidomain proteins with more than 1000 amino acid residues. The sequence identity exceeds 50% within plant kingdom showing that the proteolytic domain of separases is the most conserved one. The sequence identity drops dramatically for the N-termini of separases. For example, the identity of the first 600 amino acid residues between Arabidopsis thaliana and Vitis vinifera separases does not exceed 39%. Mode of action in vivo and mechanistic differences in mitosis between organisms, overview 718194 3.4.22.49 malfunction Arabidopsis thaliana radially swollen 4 (rsw4), a temperature-sensitive mutant, harbors a mutation in At4g22970, the separase. Loss of separase function in rsw4 at the restrictive temperature is indicated by the widespread failure of replicated chromosomes to disjoin. rsw4 has neither pronounced cell cycle arrest nor anomalous spindle formation, rsw4 roots have disorganized cortical microtubules and accumulate the mitosis-specific cyclin, cyclin B1,1 708285 3.4.22.49 malfunction cells depleted of securin or separase display defective acidification of early endosomes and increased membrane recruitment of vacuolar ATPase complexes, mimicking the effect of the specific V-ATPase inhibitor Bafilomycin A1. Securin and separase depletion causes trans-Golgi network and endosome swelling independent of cell cycle. Endosome-mediated receptor degradation and recycling are also significantly impaired by securin and separase depletion, although not receptor internalization or Rab5 activity and autophagy 718433 3.4.22.49 malfunction cells that do not express both Cdc55 and securin prematurely separate their sister chromatids, leading to cell death 718177 3.4.22.49 malfunction cells that do not express both Cdc55 and securin prematurely separate their sister chromatids, leading to cell death. Mutant mice lacking securin and expressing a non-phosphorylatable separase die in embryonic stage. But mouse embryonic stem cells lacking both these separase regulations can still progress through mitosis in a timely fashion with correct chromosome segregation 718177 3.4.22.49 malfunction human cells with one hESP allele-encoding uncleavable protein and another allele harboring a single cleavage site grow slowly owing to cell cycle delay, in particular during G2/M transition, but not when it was expected, i.e. during anaphase 718194 3.4.22.49 malfunction in the cells lacking securin Pds1, Esp1 distribution is largely restricted to the cytoplasm 718194 3.4.22.49 malfunction knocking down AtESP in meiocytes using RNAi unexpectedly converts the symmetric radial microtubule systems that form after telophase II into asymmetric structures partially resembling phragmoplasts 718194 3.4.22.49 malfunction loss of either APC or separase results in a failure of the transduction of the presumed polarity signal from the centrosome cortex 718194 3.4.22.49 malfunction loss of separase blocks centriole disengagement during mitotic exit and delays assembly of new centrioles during the following S phase 708281 3.4.22.49 malfunction loss of separase function during the early mitotic divisions causes cytokinesis failure, depletion of separase causes the accumulation of RAB-11-positive vesicles at the cleavage furrow and midbody 708239 3.4.22.49 malfunction meiotic expression of ESP RNA interference blocks the removal of cohesin during both meiosis I and II, results in alterations in nonhomologous centromere association, disrupts the radial microtubule system after telophase II, and affects the proper establishment of nuclear cytoplasmic domains, resulting in the formation of multinucleate microspores 710317 3.4.22.49 malfunction mutations in the Drosophila Separase encoding gene Sse lead not only to endoreduplication but also telomeric fusions, suggesting a role for Sse in telomere capping 754836 3.4.22.49 malfunction overexpression and deregulated proteolytic activity of Separase as frequently observed in human cancers is associated with the occurrence of supernumerary centrosomes, chromosomal missegregation and aneuploidy 755097 3.4.22.49 metabolism Plk1-mediated phosphorylation of Cdc6 on residue T37 promotes the interaction of Cdc6 and Cdk1, leading to the attenuation of Cdk1 activity, release of separase, and subsequent anaphase progression 718320 3.4.22.49 additional information cells expressing wild-type Cdc6 display lower Cdk1 activity and higher separase activity than cells expressing Cdc6 mutant T37V 718320 3.4.22.49 additional information dynamics of the mitotic exit control system in budding yeast, Queralt's model, modifications, overview. Queralt's model centres around the non-proteolytic function of separase Esp1, which triggers a positive feedback in the activation of MEN by FEAR-induced release of Cdc14 718037 3.4.22.49 additional information human separase is present in cells as a part of very large protein complex, which in addition to securin contains also Cdk and cyclin B1, both able to inhibit separase. Securin, in addition to its inhibitory role, can act as a molecular chaperone of separase, essential for its proper folding. The human separase-securin complex shows a whale-type distinct elongated pattern. In this complex, securin is thought to interact with the N-part of separase spanned by the ARM repeats. The N- to C-terminus intramolecular interaction in separase molecules is considered to be necessary for their catalytic activation, and this interaction is abolished by securin binding 718194 3.4.22.49 additional information securin, in addition to its inhibitory role, can act as a molecular chaperone of separase, essential for its proper folding 718194 3.4.22.49 additional information securin, in addition to its inhibitory role, can act as a molecular chaperone of separase, essential for its proper folding. Interaction takes place between the N-terminus of separase and the C-terminus of securin 718194 3.4.22.49 additional information securin, in addition to its inhibitory role, can act as a molecular chaperone of separase, essential for its proper folding. Securin is dispensable for the growth of normal human cells. The first 156 amino acids of Esp1 seem imperative for the binding of securin Pds1, it interacts with other parts of Esp1 as well. Securin is not only a guardian of separase, but is also responsible for its translocation to the nucleus in the budding yeast 718194 3.4.22.49 physiological function binding between separase and cyclin B1 is required for the anaphase movement of unpaired sister chromatids. Separase promotes the reversal of Cdk1-mediated phosphorylation on chromosomes at anaphase onset 731697 3.4.22.49 physiological function chiasmata resolution and segregation of homologous chromosome pair. Role in DNA repair. Assembly and elongation of spindle at mitotic anaphase. Spindle formation in meiosis. Karyokinesis (division of nucleus). Spindle midzone assembly. Apoptosis promotion. Cleavage of Slk19. Cdc14 activation and release of Cdc14 from nucleolus 754237 3.4.22.49 physiological function chromosomal segregation is mediated by cyclin-dependent kinase 1 and separase, which is regulated by cell division cycle 6, Cdc6, a mitotic substrate of polo-like kinase 1. The phosphorylation of Cdc6 by Plk1 regulates the activity of separase through the association with Cdk1 718320 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. Human separase is a potential oncogene and hESP transcripts are accumulated in a large number of tumors 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. Separase cleaves and removes the remaining centromeric cohesin. In plants, the molecular mechanisms regulating sister chromatid separation remain largely elusive 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. Separase cleaves and removes the remaining centromeric cohesin. In plants, the molecular mechanisms regulating sister chromatid separation remain largely elusive. AtESP plays a role in microtubule organization or cell polarity, and an additional role for AtESP beyond cohesin cleavage 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. Separase cleaves and removes the remaining centromeric cohesin. In yeasts, separase is responsible for the removal of both arm and centromeric cohesin after its phosphorylation by Cdc5 or other Plks. Esp1 action is not limited to this stage. When securin is depleted in yeast cells, the proteolytic activity of Esp1 is no longer cell cycle regulated, while Scc1 is cleaved on schedule suggesting the existence of additional regulatory elements 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. Separase cleaves and removes the remaining centromeric cohesin. In yeasts, separase is responsible for the removal of both arm and centromeric cohesin after its phosphorylation by Cdc5 or other Plks. Separase can target both centromeric cohesin and cohesin of chromosomal arms. Cohesin is implicated in transcriptional regulation in Schizosaccharomyces pombe. When securin is depleted in yeast cells, the proteolytic activity of Esp1 is no longer cell cycle regulated, while Scc1 is cleaved on schedule suggesting the existence of additional regulatory elements 718194 3.4.22.49 physiological function function of separases in metaphase to anaphase transition, overview. The activated APCCdc20/separase pathway plays a fundamental role in the establishment of the anterior-posterior axis 718194 3.4.22.49 physiological function functional role of securin and separase in the modulation of membrane traffic and protein secretion implicating regulation of V-ATPase assembly and function. Separase activity is controlled by securin, i.e. pituitary tumor transforming gene 1, PTTG1, a member of a divergent class of anaphase inhibitors whose proteosomal degradation by the anaphase promoting complex, APC, is required to release separase and allow its activation 718433 3.4.22.49 physiological function involved in proper positioning of the centrosomes during the first asymmetric mitotic division, in the development of egg shell and in membrane trafficking 754237 3.4.22.49 physiological function plant separase, in addition to cleaving cohesin, regulates cyclin B1,1, with profound ramifications for morphogenesis 708285 3.4.22.49 physiological function role in DNA repair. Involved in positioning of spindle pole body -, 754237 3.4.22.49 physiological function separase acts directly on Scc1 and also indirectly, through inhibition of PP2ACdc55, to stimulate cohesin cleavage, providing a feedforward loop that may contribute to a robust and timely anaphase. PP2A activity is inhibited by separase during anaphase, triggering activation of the Cdc14 mitotic phosphatase 731698 3.4.22.49 physiological function separase acts during M phase to license centrosome duplication 708281 3.4.22.49 physiological function separase cleaves the N-tail of the CENP-A related protein CPAR-1 at the meiosis I metaphase-anaphase transition 755087 3.4.22.49 physiological function separase cleaves the proteins that maintain the cohesion between sister chromatids -, 755059 3.4.22.49 physiological function separase Esp1 is a protease specialized in the cleavage of sister chromatid cohesion. When inhibitor securin Pds1 is degraded, Esp1 is activated, and cells transit into anaphase. Esp1, together with Clb2- and Polo-kinases, promotes Cdc14 activation through the FEAR network. Separase also leads to the activation of Cdc14 phosphatase. The phosphatase is kept inactive in the nucleolus by Net1 throughout the cell cycle until anaphase. The proteolytic function of separase causes spindle elongation by cohesin cleavage, which activates mitotic exit network, MEN, by bringing Tem1 together with its activator Lte1 718037 3.4.22.49 physiological function Separase is essential for sister chromatid separation during anaphase II. Separase-mediated proteolytic cleavage of the alpha-kleisin subunit of the cohesin complex at the metaphase-to-anaphase transition is essential for the proper segregation of chromosomes. Separase is also involved in mitotic and meiotic anaphase spindle assembly and elongation, interphase spindle pole body positioning, and epithelial cell reorganization 710317 3.4.22.49 physiological function separase is required at the onset of anaphase to cleave cohesin and thereby enable sister chromatid separation. The enzyme also promotes release of the Cdc14 phosphatase from the nucleolus to enable mitotic exit. The enzyme serves two roles to mediate Ty1 transposition, one to remove cohesin and the second to target Ty1-IN to chromatin 732670 3.4.22.49 physiological function separase is required for cytokinesis by regulating the incorporation of RAB-11-positive vesicles into the plasma membrane at the cleavage furrow and midbody 708239 3.4.22.49 physiological function separase is required for homolog and sister disjunction during Drosophila melanogaster male meiosis, but not for biorientation of sister centromeres 755061 3.4.22.49 physiological function separase is required for the separation of sister-chromatides in mitotic anaphase, triggers centriole disengagement during centrosome duplication. In cancer, separase is frequently overexpressed, pointing to a functional role as an aneuploidy promoter associated with centrosomal amplification and genomic instability 732703 3.4.22.49 physiological function separase plays a pivotal role in the separation of sister chromatids at anaphase by cleaving its substrate cohesin Rad21 707105 3.4.22.49 physiological function Separase plays an evolutionarily conserved role in telomere protection 754836 3.4.22.49 physiological function sister chromatid cohesion depends on the cohesin complex, a proteinaceous ring that entraps the chromatids together. At the metaphase-to-anaphase transition, separase is activated and completely dissolves the cohesion by cleaving SCC1, a subunit of the cohesin complex. As one of the key executors of anaphase, separase is regulated temporally and spatially by often redundant mechanisms. Chromosomal DNA dependent cohesin cleavage by separase is a component of a regulatory pathway that cells utilize to protect the bulk of cohesin. Degradation of securin plays a critical role in the timely activation of separase activity. But securin-independent separase regulation occur, cohesin cleavage is inhibited by a PP2ACdc55-dependent mechanism. Most of the budding yeast cohesin is cleaved in anaphase, and this cleavage is stimulated by phosphorylation of the Scc1 subunit by the Plk1 kinase 718177 3.4.22.49 physiological function sister chromatid cohesion depends on the cohesin complex, a proteinaceous ring that entraps the chromatids together. At the metaphase-to-anaphase transition, separase is activated and completely dissolves the cohesion by cleaving SCC1, a subunit of the cohesin complex. As one of the key executors of anaphase, separase is regulated temporally and spatially by often redundant mechanisms. Chromosomal DNA dependent cohesin cleavage by separase is a component of a regulatory pathway that cells utilize to protect the bulk of cohesin. Degradation of securin plays a critical role in the timely activation of separase activity. In vertebrate cells, separase is phosphorylated and inhibited before anaphase by a cyclin B/CDK1. Nuclear exclusion of separase might provide the means to preclude cohesin cleavage at telophase and G1 stage of the cell cycle 718177 3.4.22.49 physiological function sister chromatid separation at anaphase is triggered by cleavage of the cohesin subunit Scc1, which is mediated by separase 709217 3.4.22.49 physiological function the enzyme cleaves the Scc1/Rad21 subunit of cohesin, thereby triggering chromosome segregation 732187 3.4.22.49 physiological function the enzyme is involved in cell expansion 754237 3.4.22.49 physiological function the enzyme is involved in establishment of cell polarity and cytokinesis, in microtubule polymerization and Kin7 activation 754237 3.4.22.49 physiological function the enzyme is involved in reorganization and dynamics in epithelial cells, in telomere capping and in inactivation of alternative conjunction at anaphase I onset 754237 3.4.22.49 physiological function the enzyme is required for centrosome duplication and separation of sister-chromatides in anaphase of mitosis 755097 3.4.22.49 physiological function the enzyme resolves sister chromatid cohesion during the metaphase-to-anaphase transition and plays a pivotal role in chromosomal segregation and cell division. In addition to its canonical role in the dissolution of chromosomal cohesin during metaphase to anaphase transition, separase is also implicated in centrosome cycle, membrane trafficking and DNA-damage repair 752903 3.4.22.49 physiological function the enzyme resolves sister chromatid cohesion during the metaphase-to-anaphase transition and plays a pivotal role in chromosomal segregation and cell division. Separase is oncogenic, and its overexpression is sufficient to induce mammary tumours in mice. Either acute or chronic overexpression of separase in mouse mammary glands leads to aneuploidy and tumorigenesis, and inhibition of separase enzymatic activity decreases the growth of human breast tumour xenografts in mice 752903