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06:52
Induction of Mouse Lung Injury by Endotracheal Injection of Bleomycin
Published on: April 30, 2019
Human bleomycin hydrolase binds ribosomal proteins.
R P Koldamova1, I M Lefterov, M T DiSabella
1Department of Pharmacology, University of Pittsburgh School of Medicine, Pennsylvania 15261, USA.
Biochemistry
|June 3, 1999
Summary
Human bleomycin hydrolase (hBH), an enzyme that inactivates the anticancer drug bleomycin, interacts with ribosomal proteins. This study reveals hBH
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Bleomycin hydrolase (BH) is a cysteine proteinase crucial for inactivating the anticancer drug bleomycin.
- Yeast BH exhibits a homohexameric structure akin to a 20S proteasome, with known binding to single-stranded RNA and DNA.
Purpose of the Study:
- To investigate the cellular localization and binding partners of human bleomycin hydrolase (hBH).
- To determine if hBH interacts with ribosomal proteins and identify its subcellular location.
Main Methods:
- Yeast two-hybrid system to identify hBH binding partners.
- In vitro co-precipitation assays using 35S-labeled proteins.
- Immunofluorescence microscopy to confirm colocalization.
- Differential centrifugation and Western immunoblotting to analyze subcellular fractions.
- In vitro binding assays with microsomes.
Main Results:
- Human BH (hBH) was found to interact with and colocalize with ribosomal proteins L11 and L29.
- The N-terminus of hBH, including the catalytic Cys93, was essential for binding to L11.
- hBH activity and the protein itself were detected in the ribosomal subcellular fraction.
- Recombinant hBH demonstrated binding to microsomes in vitro.
Conclusions:
- Human BH (hBH) functions not only as a free cytosolic enzyme but also associates with ribosomes.
- These findings suggest a novel role for hBH in ribosome-associated cellular processes.
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