SUSP1 antagonizes formation of highly SUMO2/3-conjugated species

• Published in: The Journal of cell biology 2006-09, Vol.174 (7), p.939-949
• Main Authors: Mukhopadhyay, Debaditya, Ayaydin, Ferhan, Kolli, Nagamalleswari, Tan, Shyh-Han, Anan, Tadashi, Kametaka, Ai, Azuma, Yoshiaki, Wilkinson, Keith D, Dasso, Mary
• Format: Article
• Language: English
• Subjects: Antibodies; B lymphocytes; Cell Line, Tumor; Cell lines; Cell nucleus; Cellular biology; Cysteine Endopeptidases - analysis; Cysteine Endopeptidases - pharmacology; Cysteine Endopeptidases - physiology; Endopeptidases - classification; Enzymes; Fluorescence; HeLa Cells; Humans; Lamins; Multiprotein Complexes - analysis; Multiprotein Complexes - antagonists & inhibitors; Multiprotein Complexes - metabolism; Neoplasm Proteins - chemistry; Neoplasm Proteins - metabolism; Nuclear Proteins - chemistry; Nuclear Proteins - metabolism; Phylogeny; Promyelocytic Leukemia Protein; Protease inhibitors; Proteins; Small interfering RNA; Small Ubiquitin-Related Modifier Proteins - analysis; Small Ubiquitin-Related Modifier Proteins - antagonists & inhibitors; Small Ubiquitin-Related Modifier Proteins - metabolism; Substrate Specificity; Sumo; Transcription Factors - chemistry; Transcription Factors - metabolism; Tumor Suppressor Proteins - chemistry; Tumor Suppressor Proteins - metabolism; Ubiquitins - analysis; Ubiquitins - antagonists & inhibitors; Ubiquitins - metabolism
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.200510103

Small ubiquitin-related modifier (SUMO) processing and deconjugation are mediated by sentrin-specific proteases/ubiquitin-like proteases (SENP/Ulps). We show that SUMO-specific protease 1 (SUSP1), a mammalian SENP/Ulp, localizes within the nucleoplasm. SUSP1 depletion within cell lines expressing enhanced green fluorescent protein (EGFP) fusions to individual SUMO paralogues caused redistribution of EGFP-SUMO2 and -SUMO3, particularly into promyelocytic leukemia (PML) bodies. Further analysis suggested that this change resulted primarily from a deficit of SUMO2/3-deconjugation activity. Under these circumstances, PML bodies became enlarged and increased in number. We did not observe a comparable redistribution of EGFP-SUMO1. We have investigated the specificity of SUSP1 using vinyl sulfone inhibitors and model substrates. We found that SUSP1 has a strong paralogue bias toward SUMO2/3 and that it acts preferentially on substrates containing three or more SUMO2/3 moieties. Together, our findings argue that SUSP1 may play a specialized role in dismantling highly conjugated SUMO2 and -3 species that is critical for PML body maintenance.