Format

Send to

Choose Destination
Cell Death Differ. 2006 Nov;13(11):1866-78. Epub 2006 Feb 24.

Coupling caspase cleavage and ubiquitin-proteasome-dependent degradation of SSRP1 during apoptosis.

Author information

1
Department of Biochemistry and Molecular Biology, Oregon Health and Science University, Portland, OR 97239, USA.

Abstract

Structure-specific recognition protein (SSRP1) is an 87 kDa protein that heterodimerizes with Spt16 to form FACT, a complex initially shown to facilitate chromatin transcription. Despite its crucial roles in transcription and replication, little is known about the dynamics of FACT turnover in vivo. Here, we show that SSRP1 is cleaved during apoptosis by caspase 3 and/or 7 at the DQHD(450) site. Analysis of the resulting fragments suggests that cleavage of SSRP1 generates a truncated, chromatin-associated form of FACT. Furthermore, the N-terminal product is stabilized by proteasome inhibitors and ubiquitylated in cells, suggesting degradation through the ubiquitin-proteasome pathway. These results demonstrate that SSRP1 degradation during apoptosis is a two-step process coupling caspase cleavage and ubiquitin-dependent proteolysis.

PMID:
16498457
DOI:
10.1038/sj.cdd.4401878
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Nature Publishing Group
Loading ...
Support Center