| RRC ID |
1412
|
| 著者 |
den Engelsman J, Bennink EJ, Doerwald L, Onnekink C, Wunderink L, Andley UP, Kato K, de Jong WW, Boelens WC.
|
| タイトル |
Mimicking phosphorylation of the small heat-shock protein alphaB-crystallin recruits the F-box protein FBX4 to nuclear SC35 speckles.
|
| ジャーナル |
Eur J Biochem
|
| Abstract |
The mammalian small heat shock protein alphaB-crystallin can be phosphorylated at three different sites, Ser19, Ser45 and Ser59. We compared the intracellular distribution of wild-type, nonphosphorylatable and all possible pseudophosphorylation mutants of alphaB-crystallin by immunoblot and immunocytochemical analyses of stable and transiently transfected cells. We observed that pseudophosphorylation at two (especially S19D/S45D) or all three (S19D/S45D/S59D) sites induced the partial translocation of alphaB-crystallin from the detergent-soluble to the detergent-insoluble fraction. Double immunofluorescence studies showed that the pseudophosphorylation mutants localized in nuclear speckles containing the splicing factor SC35. The alphaB-crystallin mutants in these speckles were resistant to mild detergent treatment, and also to DNase I or RNase A digestion, indicating a stable interaction with one or more speckle proteins, not dependent on intact DNA or RNA. We further found that FBX4, an adaptor protein of the ubiquitin-protein isopeptide ligase SKP1/CUL1/F-box known to interact with pseudophosphorylated alphaB-crystallin, was also recruited to SC35 speckles when cotransfected with the pseudophosphorylation mutants. Because SC35 speckles also react with an antibody against alphaB-crystallin endogenously phosphorylated at Ser45, our findings suggest that alphaB-crystallin has a phosphorylation-dependent role in the ubiquitination of a component of SC35 speckles.
|
| 巻・号 |
271(21)
|
| ページ |
4195-203
|
| 公開日 |
2004-11-1
|
| DOI |
10.1111/j.1432-1033.2004.04359.x
|
| PII |
EJB4359
|
| PMID |
15511225
|
| MeSH |
Binding Sites
Cell Nucleus / metabolism*
Deoxyribonuclease I / metabolism
Detergents / pharmacology
Endopeptidases / metabolism
F-Box Proteins / chemistry*
HeLa Cells
Humans
Immunoblotting
Immunohistochemistry
Microscopy, Fluorescence
Mutation
Nuclear Proteins / metabolism*
Phosphorylation
Plasmids / metabolism
Protein Binding
Protein Transport
Ribonuclease, Pancreatic / metabolism
Ribonucleoproteins / metabolism*
Serine / chemistry
Serine-Arginine Splicing Factors
Subcellular Fractions / metabolism
Ubiquitin / metabolism
alpha-Crystallin B Chain / chemistry*
alpha-Crystallin B Chain / metabolism
|
| 引用数 |
59
|
|
WOS 分野
|
BIOCHEMISTRY & MOLECULAR BIOLOGY
|
| リソース情報 |
| ヒト・動物細胞 |
anti-αB-crystallin(RCB1304) |
