1. SUMO Regulates the Assembly and Function of a Cytoplasmic Intermediate Filament Protein in C. elegans
- Author
-
Kaminsky, Rachel, Denison, Carilee, Bening-Abu-Shach, Ulrike, Chisholm, Andrew D., Gygi, Steven P., and Broday, Limor
- Subjects
- *
CYTOPLASMIC filaments , *INTERMEDIATE filament proteins , *CELL division , *CHROMOSOMES , *DNA damage , *PROTEOMICS , *CELLULAR control mechanisms , *CAENORHABDITIS elegans - Abstract
Summary: Sumoylation is a reversible posttranslational modification that plays roles in many processes, including transcriptional regulation, cell division, chromosome integrity, and DNA damage response. Using a proteomics approach, we identified ∼250 candidate targets of sumoylation in C. elegans. One such target is the cytoplasmic intermediate filament (cIF) protein named IFB-1, which is expressed in hemidesmosome-like structures in the worm epidermis and is essential for embryonic elongation and maintenance of muscle attachment to the cuticle. In the absence of SUMO, IFB-1 formed ectopic filaments and protein aggregates in the lateral epidermis. Moreover, depletion of SUMO or mutation of the SUMO acceptor site on IFB-1 resulted in a reduction of its cytoplasmic soluble pool, leading to a decrease in its exchange rate within epidermal attachment structures. These observations indicate that SUMO regulates cIF assembly by maintaining a cytoplasmic pool of nonpolymerized IFB-1, and that this is necessary for normal IFB-1 function. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF