An Inducible Retroviral Expression System for Tandem Affinity Purification Mass-Spectrometry-Based Proteomics Identifies Mixed Lineage Kinase Domain-like Protein (MLKL) as an Heat Shock Protein 90 (HSP90) Client

Clinical resistance to imatinib mesylate is commonly observed in patients with advanced Philadelphia chromosome– positive (Ph+) leukemias. Acquired resistance is typically associated with reactivation of BCR-ABL due to kinase domain mutations or gene amplification, indicating that BCR-ABL remains a viable target for inhibition in these patients. Strategies for overcoming resistance can be envisioned through exploitation of other molecular features of the BCR-ABL protein, such as its dependence on the molecular chaperone heat shock protein 90 (Hsp90). To determine whether inhibition of Hsp90 could induce degradation of imatinib mesylate–resistant, mutant BCR-ABL proteins, hematopoietic cells expressing 2 mutant BCR-ABL proteins found in imatinib mesylate–resistant patients (T315I and E255K) were examined for sensitivity to geldanamycin and 17-allylaminogeldanamycin (17-AAG). Both compounds induced the degradation of wild-type and mutant BCR-ABL and inhibited cell growth, with a trend indicating more potent activity against mutant BCR-ABL proteins. These data support clinical investigations of 17-AAG in imatinib mesylate–resistant Ph+ leukemias.

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Identification of Protein Complexes from Tandem Affinity Purification/Mass Spectrometry Data via Biased Random Walk

IEEE/ACM Transactions on Computational Biology and Bioinformatics ◽

10.1109/tcbb.2014.2352616 ◽

2015 ◽

Vol 12 (2) ◽

pp. 455-466 ◽

Cited By ~ 3

Author(s):

Bingjing Cai ◽

Haiying Wang ◽

Huiru Zheng ◽

Hui Wang

Keyword(s):

Mass Spectrometry ◽

Random Walk ◽

Protein Complexes ◽

Affinity Purification ◽

Tandem Affinity Purification ◽

Mass Spectrometry Data ◽

Biased Random Walk ◽

Affinity Purification Mass Spectrometry

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Heat-shock protein 90 and Cdc37 interact with LKB1 and regulate its stability

Biochemical Journal ◽

10.1042/bj20021813 ◽

2003 ◽

Vol 370 (3) ◽

pp. 849-857 ◽

Cited By ~ 57

Author(s):

Jérôme BOUDEAU ◽

Maria DEAK ◽

Margaret A. LAWLOR ◽

Nick A. MORRICE ◽

Dario R. ALESSI

Keyword(s):

Heat Shock ◽

Protein Kinase ◽

Heat Shock Protein ◽

Heat Shock Protein 90 ◽

Kinase Domain ◽

Cancer Syndrome ◽

Hsp90 Inhibitors ◽

Detailed Mechanism ◽

Anti Cancer ◽

Hsp90 Chaperone

LKB1 is a widely expressed serine/threonine protein kinase that is mutated in the inherited Peutz—Jeghers cancer syndrome. Recent findings indicate that LKB1 functions as a tumour suppressor, but little is known regarding the detailed mechanism by which LKB1 regulates cell growth. In this study we have purified LKB1 from cells and establish that it is associated with the heat-shock protein 90 (Hsp90) chaperone and the Cdc37 kinase-specific targetting subunit for Hsp90. We demonstrate that Cdc37 and Hsp90 bind specifically to the kinase domain of LKB1. We also perform experiments using Hsp90 inhibitors, which indicate that the association of Hsp90 and Cdc37 with LKB1 regulates LKB1 stability and prevents its degradation by the proteasome. Hsp90 inhibitors are being considered as potential anti-cancer agents. However, our observations indicate that prolonged usage of these drugs could possibly lead to tumour development by decreasing cellular levels of LKB1.

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