Pellino-1, an adaptor protein of interleukin-1 receptor/toll-like receptor signaling, is sumoylated by Ubc9.
Covalent modifications of the Pellino-1 protein are essential for transmitting innate immune response signals downstream, as the phosphorylation and polyubiquitination of Pellino-1 mediated by the IRAK proteins appear to have roles in regulating Pellino-1 function. In this study, we demonstrate that the Pellino-1 protein is post-translationally modified by small-ubiquitin-related modifier-1 (SUMO-1). Sumoylation assays with Pellino-1 and SUMO-1 expression plasmids reveal that the Pellino-1 protein is sumoylated in vitro and in vivo. Treatment of SUMO-1 specific protease 1 (SENP1) inhibited the sumoylation of the Pellino-1 protein and a GST pull-down assay as well as a yeast two hybrid assay showed that Pellino-1 binds to the SUMO-conjugating enzyme, Ubc9. Furthermore, we identified the five lysine residues of the Pellino-1 protein where SUMO-1 covalently attaches. Some of the sumoylated sites overlap with previously identified ubiquitination sites, suggesting competition between sumoylation and ubiquitination, as well as suggesting that the sumoylated Pellino-1 protein may have a cellular function distinct from previously identified functions.
Department of Biological Sciences, Sungkyunkwan University, Suwon 440-746, Korea.
Jun Hwan
JH
Kim
Ki Sa
KS
Sung
Su Myung
SM
Jung
Youn Sook
YS
Lee
Jae Young
JY
Kwon
Cheol Yong
CY
Choi
Seok Hee
SH
Park
D006367:HeLa Cells; D006801:Humans; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017472:Receptors, Interleukin-1 / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D025842:SUMO-1 Protein / Q000378:metabolism; D015398:Signal Transduction; D058207:Sumoylation; D051193:Toll-Like Receptors / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases; D000098843:Ubiquitin-Conjugating Enzyme UBC9
D050505:Mutant Proteins; D009687:Nuclear Proteins; D017472:Receptors, Interleukin-1; D011993:Recombinant Fusion Proteins; D025842:SUMO-1 Protein; D051193:Toll-Like Receptors; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases; C418046:Peli1 protein, mouse; D000098843:Ubiquitin-Conjugating Enzyme UBC9