Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P43146 (tumour suppressor)
 5,935 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Von Hippel-Lindau disease (VHL) is caused by germline mutations in the VHL tumour suppressor gene. Tumour development in this setting is due to loss or inactivation of the remaining wild-type VHL allele. The VHL gene product (pVHL) resides primarily in the cytoplasm. A frequently mutated region of pVHL can bind to complexes containing elongin B, elongin C and Cul2. Loss of pVHL leads to an inappropriate accumulation of hypoxia-inducible mRNAs, such as the mRNA encoding vascular endothelial growth factor (VEGF), under normoxic conditions. This finding is most likely to account for the hypervascular nature of VHL-associated neoplasms. Current studies are focussed on understanding if and how binding to elongins and Cul2 is linked to the ability of pVHL to regulate hypoxia-inducible mRNAs. In this regard, it is perhaps noteworthy that elongin C and Cul2 are homologous to yeast proteins Skp1 and Cdc53. These latter proteins participate in the formation of complexes that target certain proteins for ubiquitination.
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PMID:Functions of the von Hippel-Lindau tumour suppressor protein. 968 55

von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome caused by germline mutations of the VHL tumour suppressor gene. The VHL gene product, pVHL, forms multiprotein complexes that contain elongin B, elongin C and Cul-2, and negatively regulates hypoxia-inducible mRNAs. pVHL is suspected to play a role in ubiquitination given the similarity of elongin C and Cul-2 with Skp1 and Cdc53, respectively. pVHL can also interact with fibronectin and is required for the assembly of a fibronectin matrix. Finally, pVHL, at least indirectly, plays a role in the ability of cells to exit the cell cycle. Thus, pVHL is a tumour suppressor protein that regulates angiogenesis, extracellular matrix formation and the cell cycle.
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PMID:The von Hippel-Lindau tumour suppressor protein: new perspectives. 1036 21

The von Hippel-Lindau tumour suppressor gene product (pVHL) associates with the elongin B and C and Cul2 proteins to form a ubiquitin-ligase complex (VCBC). To date, the only VCBC substrates identified are the hypoxia-inducible factor alpha subunits (HIF-1alpha and HIF-2alpha). However, pVHL is thought to have multiple functions and the significance of HIF-1alpha and HIF-2alpha regulation for tumour suppressor activity has not been defined. VHL disease is characterized by distinct clinical subtypes. Thus haemangioblastomas (HABs) and renal cell carcinoma (RCC) but not phaeochromocytoma (PHE) occur in type 1 VHL disease. Type 2 subtypes are characterized by PHE susceptibility but differ with respect to additional tumours (type 2A, PHE+HAB but not RCC; type 2B, PHE+ HAB+RCC; type 2C, PHE only). We investigated in detail the effect of 13 naturally occurring VHL mutations (11 missense), representing each phenotypic subclass, on HIF-alpha subunit regulation. Consistent effects on pVHL function were observed for all mutations within each subclass. Mutations associated with the PHE-only phenotype (type 2C) promoted HIF-alpha ubiquitylation in vitro and demonstrated wild-type binding patterns with pVHL interacting proteins, suggesting that loss of other pVHL functions are necessary for PHE susceptibility. Mutations causing HAB susceptibility (types 1, 2A and 2B) demonstrated variable effects on HIF-alpha subunit and elongin binding, but all resulted in defective HIF-alpha regulation and loss of p220 (fibronectin) binding. All RCC-associated mutations caused complete HIF-alpha dysregulation and loss of p220 (fibronectin) binding. Our findings are consistent with impaired ability to degrade HIF-alpha subunit being required for HAB development and RCC susceptibility.
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PMID:Contrasting effects on HIF-1alpha regulation by disease-causing pVHL mutations correlate with patterns of tumourigenesis in von Hippel-Lindau disease. 1133 13

The von Hippel-Lindau (VHL) tumour suppressor protein is important in the E3 ubiquitin ligase ECV (Elongin B/C-CUL2-VHL)-mediated destruction of hypoxia-inducible factor and the promotion of fibronectin (FN) extracellular matrix assembly. Although the precise molecular mechanism controlling the selectivity of VHL function remains unknown, a failure in either process is associated with oncogenic progression. Here, we show that VHL performs its FN-associated function independently of the ECV complex, highlighting the autonomy of these pathways. Furthermore, we show that NEDD8, a ubiquitin-like molecule, acts as a 'molecular switch' in which its covalent conjugation to VHL prohibits the engagement of the scaffold component CUL2 and, concomitantly, activates the association with FN. These findings provide the first mechanistic step in defining the functional selectivity of VHL and explain a previously unrecognized function of NEDD8.
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PMID:NEDD8 acts as a 'molecular switch' defining the functional selectivity of VHL. 1832 57