A 19S proteasomal subunit cooperates with an ERK MAPK-regulated degron to regulate accumulation of Fra-1 in tumour cells
|Title:||A 19S proteasomal subunit cooperates with an ERK MAPK-regulated degron to regulate accumulation of Fra-1 in tumour cells||Authors:||Pakay, J. L.
|Permanent link:||http://hdl.handle.net/10197/5077||Date:||29-Aug-2011||Online since:||2013-11-29T10:19:42Z||Abstract:||Fos-related antigen-1 (Fra-1) is a member of the Activator Protein-1 (AP-1) transcription factor superfamily that is overexpressed in a variety of cancers, including colon, breast, lung, bladder and brain. High Fra-1 levels are associated with enhanced cell proliferation, survival, migration and invasion. Despite its frequent overexpression, the molecular mechanisms that regulate the accumulation of Fra-1 proteins in tumour cells are not well understood. Here, we show that turnover of Fra-1, which does not require ubiquitylation, is cooperatively regulated by two distinct mechanisms—association with the 19S proteasomal subunit, TBP-1, and by a C-terminal degron, which acts independently of TBP-1, but is regulated by RAS–ERK (extracellular signal-regulated kinase) signalling. TBP-1 depletion stabilized Fra-1 and further increased its levels in tumour cells expressing RAS–ERK pathway oncogenes. These effects correlated with increased AP-1 transcriptional activity. We suggest that during Fra-1 degradation, association with TBP-1 provides a mechanism for ubiquitin-independent proteasomal recognition, while the C terminus of the protein regulates its subsequent proteolytic processing.||Type of material:||Journal Article||Publisher:||Nature Publishing Group||Journal:||Oncogene||Volume:||31||Issue:||14||Start page:||1817||End page:||1824||Copyright (published version):||2011 Nature Publishing Group||Keywords:||Fra-1; turnover; TBP-1; cancer; ERK; RAS||DOI:||10.1038/onc.2011.375||Language:||en||Status of Item:||Peer reviewed|
|Appears in Collections:||SBI Research Collection|
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