Human Retinoblastoma Binding Protein 9, a Serine Hydrolase Implicated in Pancreatic Cancers

Author(s): Sergey M. Vorobiev, Yuanpeng Janet Huang, Jayaraman Seetharaman, Rong Xiao, Thomas B. Acton, Gaetano T. Montelione, Liang Tong.

Journal Name:Protein & Peptide Letters

Volume 19 , Issue 2 , 2012

Abstract:

Human retinoblastoma binding protein 9 (RBBP9) is an interacting partner of the retinoblastoma susceptibility protein (Rb). RBBP9 is a tumor-associated protein required for pancreatic neoplasia, affects cell cycle control, and is involved in the TGF-β signalling pathway. Sequence analysis suggests that RBBP9 belongs to the α/β hydrolase superfamily of enzymes. The serine hydrolase activity of RBBP9 is required for development of pancreatic carcinomas in part by inhibiting TGF-β antiproliferative signaling through suppressing Smad2/3 phosphorylation. The crystal structure of human RBBP9 confirms the α/β hydrolase fold, with a six-stranded parallel β-sheet flanked by α helixes. The structure of RBBP9 resembles that of the YdeN protein from Bacillus subtilis, which is suggested to have carboxylesterase activity. RBBP9 contains a Ser75-His165-Asp138 catalytic triad, situated in a prominent pocket on the surface of the protein. The side chains of the LxCxE sequence motif that is important for interaction with Rb is mostly buried in the structure. Structure- function studies of RBBP9 suggest possible routes for novel cancer drug discovery programs.

Keywords: α/β hydrolase, pancreatic cancer, protein structure, structural genomics, RBBP9, antiproliferative, Smad2/3 phosphorylation, Bacillus subtilis, Ser75, emetine, E-cadherin

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Article Details

VOLUME: 19
ISSUE: 2
Year: 2012
Page: [194 - 197]
Pages: 4
DOI: 10.2174/092986612799080356
Price: $58