Coronin7 forms a novel E3 ubiquitin ligase complex to promote the degradation of the anti-proliferative protein Tob

Watanabe, Makoto; Suzuki, Toru; Kim, Minsoo; Abe, Yoshinori; Yoshida, Yutaka; Sugano, Sumio; Yamamoto, Tadashi

doi:10.1016/j.febslet.2010.11.049

Cited by 2 publications

(3 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…24) These results suggest overall that the effects of a specific ubiquitin ligase may predominate, depending on the cell type or the malignant level of cancer, and that the polyubiquitination of BTG1 and BTG2 may be mediated by not one, but multiple ubiquitin ligases. To support this hypothesis, the SCF-like ubiquitin ligase complex containing CRN7, together with the SCF complex containing Skp2, 23) was recently shown to promote the polyubiquitination of Tob, 25) a member of the BTG/Tob family. It should be noted that CRN7 interacts with Tob through the WD40 repeat motif, 25) while Skp2 does through the leucine-rich repeat motif.…”

Section: Kip1mentioning

confidence: 99%

“…To support this hypothesis, the SCF-like ubiquitin ligase complex containing CRN7, together with the SCF complex containing Skp2, 23) was recently shown to promote the polyubiquitination of Tob, 25) a member of the BTG/Tob family. It should be noted that CRN7 interacts with Tob through the WD40 repeat motif, 25) while Skp2 does through the leucine-rich repeat motif. 23) Thus, it can be inferred that these interaction manners in Tob are similar to those in BTG, in which BTG interacts with either βTrCP, containing the WD40 repeat motif, or Skp2, containing the leucine-rich repeat motif.…”

Section: Kip1mentioning

confidence: 99%

“…24) On the other hand, Coronin 7 (CRN7) has been identified as a novel component of an SCF-like ubiquitin ligase complex, functioning in the polyubiquitination of Tob. 25) Therefore, it is possible that the protein stability of BTG/Tob family members is controlled by multiple ubiquitin ligase complexes, including SCF Skp2 . In this report, we present evidence showing that the SCF complex, containing β-transducin repeat-containing protein 1 (βTrCP1) as an F-box protein, promoted the polyubiquitination of both BTG1 and BTG2 more efficiently than the SCF complex containing Skp2 as the F-box protein.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Polyubiquitination of the B-Cell Translocation Gene 1 and 2 Proteins Is Promoted by the SCF Ubiquitin Ligase Complex Containing βTrCP

Sasajima

Nakagawa

Kashiwayanagi

et al. 2012

Biological & Pharmaceutical Bulletin

View full text Add to dashboard Cite

B-cell translocation gene 1 and 2 (BTG1 and BTG2) are members of the BTG/Tob antiproliferative protein family, which is able to regulate the cell cycle and cell proliferation. We previously reported that BTG1, BTG2, Tob, and Tob2 are degraded via the ubiquitin-proteasome pathway. In this study, we investigated the mechanism of polyubiquitination of BTG1 and BTG2. Since the Skp1-Cdc53/Cullin 1-F-box protein (SCF) complex functions as one of the major ubiquitin ligases for cell cycle regulation, we first examined interactions between BTG proteins and components of the SCF complex, and found that BTG1 and BTG2 were capable of interacting with the SCF complex containing Cullin-1 (a scaffold protein) and Skp1 (a linker protein). As the SCF complex can ubiquitinate various target proteins by substituting different F-box proteins as subunits that recognize different target proteins, we next examined which F-box proteins could bind the two BTG proteins, and found that Skp2, β-transducin repeat-containing protein 1 (βTrCP1), and βTrCP2 were able to associate with both BTG1 and BTG2. Furthermore, we obtained evidence showing that βTrCP1 enhanced the polyubiquitination of both BTG1 and BTG2 more efficiently than Skp2 did, and that an F-box truncated mutant of βTrCP1 had a dominant negative effect on this polyubiquitination. Thus, we propose that BTG1 and BTG2 are subjected to polyubiquitination, more efficiently when it is mediated by SCF βTrCP than by SCF Skp2 .Key words antiproliferative protein; B-cell translocation gene; ubiquitin ligase; Skp1-Cdc53/Cullin 1-F-box protein; F-box protein; ubiquitin B-cell translocation gene 1 and 2 (BTG1 and BTG2) proteins belong to the BTG/transducer of ErbB2 (Tob) antiproliferative protein family, which shares a highly conserved N-terminal domain that bears no similarity to any other known domain.1,2) The exogenous expression of BTG/Tob family members results in the inhibition of cell proliferation in a variety of cell types, [3][4][5][6] implying that the BTG/Tob family is a novel class of protein family involved in cell cycle progression, cell proliferation, and tumor suppression. In fact, BTG/ Tob expression is reduced in several cancer tissues. 7,8) Intriguingly, the conserved BTG/Tob domain is implicated as a region that allows for interaction with a variety of transcription factors, suggesting that BTG/Tob contributes to the regulation of DNA-binding of sequence-specific transcription factors. [9][10][11] BTG/Tob family members also interact with subunit 7 of the chemokine (C-C motif) receptor 4 (CCR4)-negative regulator of transcription (NOT) complex (CNOT7) or CNOT8 6,[12][13][14] ; the CCR4-NOT complex regulates transcription and mRNA turnover.15,16) Furthermore, it was reported that BTG2 and Tob participate in mRNA turnover by promoting mRNA deadenylating activity of the CCR4-NOT complex.

show abstract