Drosophila von Hippel-Lindau Tumor Suppressor Complex Possesses E3 Ubiquitin Ligase Activity

ABSTRACT We examined the biogenesis of the von Hippel-Lindau (VHL) tumor suppressor protein (pVHL) in vitro and in vivo. pVHL formed a complex with the cytosolic chaperonin containing TCP-1 (CCT or TRiC) en route to assembly with elongin B/C and the subsequent formation of the VCB-Cul2 ubiquitin ligase. Blocking the interaction of pVHL with elongin B/C resulted in accumulation of pVHL within the CCT complex. pVHL present in purified VHL-CCT complexes, when added to rabbit reticulocyte lysate, proceeded to form VCB and VCB-Cul2. Thus, CCT likely functions, at least in part, by retaining VHL chains pending the availability of elongin B/C for final folding and/or assembly. Tumor-associated mutations within exon II of the VHL syndrome had diverse effects upon the stability and/or function of pVHL-containing complexes. First, a pVHL mutant lacking the entire region encoded by exon II did not bind to CCT and yet could still assemble into complexes with elongin B/C and elongin B/C-Cul2. Second, a number of tumor-derived missense mutations in exon II did not decrease CCT binding, and most had no detectable effect upon VCB-Cul2 assembly. Many exon II mutants, however, were found to be defective in the binding to and subsequent ubiquitination of hypoxia-inducible factor 1α (HIF-1α), a substrate of the VCB-Cul2 ubiquitin ligase. We conclude that the selection pressure to mutate VHL exon II during tumorigenesis does not relate to loss of CCT binding but may reflect quantitative or qualitative defects in HIF binding and/or in pVHL-dependent ubiquitin ligase activity.

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Role of the C-terminal α-helical domain of the von Hippel–Lindau protein in its E3 ubiquitin ligase activity

Oncogene ◽

10.1038/sj.onc.1207384 ◽

2003 ◽

Vol 23 (13) ◽

pp. 2315-2323 ◽

Cited By ~ 8

Author(s):

Martin D Lewis ◽

Ben J Roberts

Keyword(s):

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Von Hippel Lindau ◽

Helical Domain ◽

Ubiquitin Ligase Activity

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Faculty Opinions recommendation of Diverse effects of mutations in exon II of the von Hippel-Lindau (VHL) tumor suppressor gene on the interaction of pVHL with the cytosolic chaperonin and pVHL-dependent ubiquitin ligase activity.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1005409.62654 ◽

2002 ◽

Author(s):

Peter Ratcliffe

Keyword(s):

Tumor Suppressor ◽

Tumor Suppressor Gene ◽

Ubiquitin Ligase ◽

Suppressor Gene ◽

Von Hippel Lindau ◽

Ubiquitin Ligase Activity

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Identification of the von Hippel-Lindau tumor-suppressor protein as part of an active E3 ubiquitin ligase complex

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.96.22.12436 ◽

1999 ◽

Vol 96 (22) ◽

pp. 12436-12441 ◽

Cited By ~ 334

Author(s):

K. Iwai ◽

K. Yamanaka ◽

T. Kamura ◽

N. Minato ◽

R. C. Conaway ◽

...

Keyword(s):

Tumor Suppressor ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Tumor Suppressor Protein ◽

Von Hippel Lindau ◽

Ubiquitin Ligase Complex

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Faculty Opinions recommendation of The E3 ubiquitin ligase activity of RING1B is not essential for early mouse development.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725799223.793526294 ◽

2016 ◽

Author(s):

Anton Wutz

Keyword(s):

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Mouse Development ◽

Ubiquitin Ligase Activity ◽

Early Mouse

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Therapeutically actionable signaling node to rescue AURKA driven loss of primary cilia in VHL-deficient cells

Scientific Reports ◽

10.1038/s41598-021-89933-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Pratim Chowdhury ◽

Dimuthu Perera ◽

Reid T. Powell ◽

Tia Talley ◽

Durga Nand Tripathi ◽

...

Keyword(s):

Ubiquitin Ligase ◽

Primary Cilia ◽

Mtor Inhibitor ◽

E3 Ubiquitin Ligase ◽

Xenograft Model ◽

Aurora Kinase ◽

Tumor Burden ◽

Aurora Kinase A ◽

Von Hippel Lindau ◽

In Cells

AbstractLoss of primary cilia in cells deficient for the tumor suppressor von Hippel Lindau (VHL) arise from elevated Aurora Kinase A (AURKA) levels. VHL in its role as an E3 ubiquitin ligase targets AURKA for degradation and in the absence of VHL, high levels of AURKA result in destabilization of the primary cilium. We identified NVP-BEZ235, a dual PI3K/AKT and mTOR inhibitor, in an image-based high throughput screen, as a small molecule that restored primary cilia in VHL-deficient cells. We identified the ability of AKT to modulate AURKA expression at the transcript and protein level. Independent modulation of AKT and mTOR signaling decreased AURKA expression in cells confirming AURKA as a new signaling node downstream of the PI3K cascade. Corroborating these data, a genetic knockdown of AKT in cells deficient for VHL rescued the ability of these cells to ciliate. Finally, inhibition of AKT/mTOR using NVP-BEZ235 was efficacious in reducing tumor burden in a 786-0 xenograft model of renal cell carcinoma. These data highlight a previously unappreciated signaling node downstream of the AKT/mTOR pathway via AURKA that can be targeted in VHL-null cells to restore ciliogenesis.

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An E3 Ubiquitin Ligase RNF139 Serves as a Tumor-Suppressor in Glioma

Journal of Molecular Neuroscience ◽

10.1007/s12031-021-01860-4 ◽

2021 ◽

Author(s):

Xiaofeng Chen ◽

Weiping Kuang ◽

Yong Zhu ◽

Bin Zhou ◽

Xiaosong Li ◽

...

Keyword(s):

Tumor Suppressor ◽

Cell Lines ◽

Ubiquitin Ligase ◽

Glioma Cell ◽

Protein Modification ◽

E3 Ubiquitin Ligase ◽

Ring Finger ◽

Glioma Cells ◽

Migration And Invasion ◽

Tissue Samples

AbstractGlioma is highly lethal because of its high malignancy. Ubiquitination, a type of ubiquitin-dependent protein modification, has been reported to play an oncogenic or tumor-suppressive role in glioma development, depending on the targets. Ring finger protein 139 (RNF139) is a membrane-bound E3 ubiquitin ligase serving as a tumor suppressor by ubiquitylation-dependently suppressing cell growth. Herein, we firstly confirmed the abnormal downregulation of RNF139 in glioma tissues and cell lines. In glioma cells, ectopic RNF139 overexpression could inhibit, whereas RNF139 knockdown could aggravate the aggressive behaviors of glioma cells, including hyperproliferation, migration, and invasion. Moreover, in two glioma cell lines, RNF139 overexpression inhibited, whereas RNF139 knockdown enhanced the phosphorylation of phosphatidylinositol 3-kinase (PI3K) and AKT serine/threonine kinase 1 (AKT). In a word, we demonstrate the aberration in RNF139 expression in glioma tissue samples and cell lines. RNF139 serves as a tumor-suppressor in glioma by inhibiting glioma cell proliferation, migration, and invasion and promoting glioma cell apoptosis through regulating PI3K/AKT signaling.

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