title: The behavior of SATB1, a MAR-binding protein, in response to apoptosis stimulation.
abstract: As a MAR-binding protein, SATB1 regulates genes by folding chromatin into a loop domain. Apoptosis is known to be accompanied by a collapse of nuclear architecture and cleavage of condensing chromatin into oligonucleosomal fragments. To further understand the functional role of MAR-binding proteins during apoptosis we investigated the relationship of the behavior of SATB1 and the collapse of nuclear architecture in Jurkat cells with immunostaining and Western blot analysis. We demonstrated that SATB1 formed special three-dimensional network distributions during early apoptosis. The distribution change of SATB1 was associated with cleavage of the protein and accompanied by the nuclear architecture collapse. Cleavage of SATB1 was mediated by caspase-3 and was apoptosis specific. Our observations further support the notion that early proteolysis of MAR-binding proteins might represent a universal mechanism that renders these DNA sites vulnerable to endonucleolysis.
authors.affiliation: Key Laboratory of Functional Genomics of Jiangsu Province, Nanjing Medical University, Hanzhong Road #140, Nanjing 210029, PR China.
authors.forename: Yujie
authors.initials: Y
authors.lastname: Sun
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Su
authors.forename: Yongmei
authors.initials: Y
authors.lastname: Yin
authors.forename: Shan
authors.initials: S
authors.lastname: Xu
authors.forename: Changyan
authors.initials: C
authors.lastname: Ma
authors.forename: Xiao
authors.initials: X
authors.lastname: Han
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D002166:Camptothecin / Q000494:pharmacology; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D015894:Genome, Human / Q000235:genetics; D006801:Humans; D019169:Jurkat Cells; D036961:Matrix Attachment Region Binding Proteins / Q000378:metabolism*; D009842:Oligopeptides / Q000494:pharmacology; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D059003:Topoisomerase Inhibitors
chemical_list: D061945:Caspase Inhibitors; D036961:Matrix Attachment Region Binding Proteins; D009842:Oligopeptides; C076189:SATB1 protein, human; D059003:Topoisomerase Inhibitors; C108637:aspartyl-glutamyl-valyl-aspartal; D004247:DNA; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D002166:Camptothecin