Methods to identify compounds useful for the treatment of proliferative and differentiative disorders

Abstract

The present invention relates to the discovery, identification and characterization of nucleotide sequences that encode novel substrate-targeting subunits of ubiquitin ligases. The invention encompasses nucleotides encoding novel substrate-targeting subunits of ubiquitin ligases: FBP1, FBP2, FBP3, FBP4, FBP5, FBP6, FBP7, FBP8, FBP9, FBP10, FBP11, FBP12, FBP13, FBP14, FBP15, FBP16, FBP17, FBP18, FBP19, FBP20, FBP21, FBP22, FBP23, FBP24, and FBP25, transgenic mice, knock-out mice, host-cell expression systems and proteins encoded by the nucleotides of the novel substrate-targeting subunits. The present invention relates to screening assays that use novel and known substrate-targeting subunits of ubiquitin ligases to identify potential therapeutic agents such as small molecules, compounds or derivatives and analogues of the novel and known ubiquitin ligases which modulate activity of the novel and known ubiquitin ligases for the treatment of proliferative and differentiative disorders, such as cancer, major opportunistic infections, immune disorders, certain cardiovascular diseases, and inflammatory disorders. The invention further encompasses therapeutic protocols and pharmaceutical compositions designed to target ubiquitin ligases and their substrates for the treatment of proliferative and differentiative disorders.

Description

1. CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation-in-part of Ser. No. 10 / 632,150, filed Jul. 30, 2003, which is a division of Ser. No. 09 / 385,219, filed Aug. 27, 1999. This application is also a continuation-in-part of Ser. No. 10 / 042,417, filed Jan. 7, 2002.2. INTRODUCTION [0002] The present invention relates to the discovery, identification and characterization of nucleotide sequences that encode novel substrate-targeting subunits of ubiquitin ligases. The invention encompasses nucleic acid molecules comprising nucleotide sequences encoding novel substrate-targeting subunits of ubiquitin ligases: FBP1, FBP2, FBP3a, FBP3b, FBP4, FBP5, FBP6, FBP7, FBP8, FBP11, FBP12, FBP13, FBP14, FBP15, FBP17, FBP18, FBP20, FBP21, FBP22, FBP23, and FBP25, transgenic mice, knock-out mice, host cell expression systems and proteins encoded by the nucleotides of the present invention. The present invention relates to screening assays to identify potential therapeutic ...

AI Technical Summary

Benefits of technology

[0029] The invention is illustrated by way of working examples which demonstrate the identification and characterization of the novel substrate-targeting subunits of ubiquitin ligase complexes. The working examples of the present invention further demonstrate the identification of the specific interaction of (i) FBP1 with β-catenin and (ii) the known FBP, Skp2, with the cell-cycle regulatory proteins E2F and p27 and the cell cycle protein Cks1. These interactions suggest that β-catenin is a specific substrate of FBP1, while E2F and p27 are substrates of Skp2 and Cks1 is a mediator for Skp2 and p27. In fact, the working examples of the present invention further demonstrate that β-catenin is a specific substrate of FBP1, while p27 is substrates of Skp2 and Cks1 binds to both p27 and Skp2. The identification of proteins interacting with the novel FBPs will be possible using the methods described herein.

Problems solved by technology

When positive signals overcome or when negative signals are absent, the cells multiply too quickly and cancer develops.

This mechanism goes awry in tumors, leading to the excessive accumulation of positive signals (oncogenic proteins), or resulting in the abnormal degradation of negative regulators (tumor suppressor proteins).

F box proteins in yeast are known to regulate genomic stability and senescence, and recent data has shown that F box inhibition in mammalian cells can lead to the loss of DNA damage checkpoints.

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