Regions within sox11 contributing to caspase-6 activity decreases include amino acids 117–214, as well as the c-terminal transactivation domain.

Abstract

<p>(A) Schematic diagram depicting sox11 deletion mutants. (B) Caspase-6 substrate assay show all deletions within sox11 caused a significant reduction in caspase-6 activity. Although sox11 mutants Δ117–187, Δ188–214, Δ117–214, ΔC33, and ΔC33 Δ117–214 appeared to cause an increased trend in caspase-6 activity, no significant increase was found when compared to wildtype sox11 (n = 3, one-way anova, Sidak’s multiple comparsion test Sox11 mutants containing deletions of amino acids 6–49, 214–296, or deletion of either the HMG domain or polyserine region retained their capacity to retard caspase-6 activity(C) Western bolt analysis of sox11 mutants (upper panel) show a large difference in expression patterns. Western blots of caspase-6 proteolysis revealed that the sox11 mutants which did not reduce caspase-6 activity to control levels were also incapable of preventing caspase-6 cleavage (lanes 7, 8, 10, 12, 13). (D) Sox11 and mutants were immunoprecipitated from lysates using anti-flag antibody. Caspase-6 was detected using anti-caspase-6 raised against the N-terminus of caspase-6.</p