Abstract
The branched-chain amino acid aminotransferase, Bcat1/Eca39, catalyzes the first step of branched-chain amino acid catabolism. Bcat1/Eca39 was originally isolated from a c-myc-induced tumor and was proven to be a direct target for c-Myc regulation. The gene is highly conserved in evolution and disruption of its yeast homolog affects cell growth. To assess the role of Bcat1/Eca39 in mammalian cells, we overexpressed Bcat1/Eca39 in murine cells and studied effects on cell growth. Overexpression of Bcat1/Eca39 had no apparent effect on the proliferation of cells grown with high serum concentrations, but under serum deprivation conditions, led to a decrease in cell viability. Cell death under these conditions displayed apoptotic features. The branched-chain keto acid, α-ketoisocaproate, a metabolite of leucine catabolism produced by BCAT1/ECA39, was previously found to inhibit cell growth. We show that α-ketoisocaproate can induce rapid apoptotic cell death. This observation suggests that the growth inhibitory effect of BCAT1/ECA39 and its apoptosis promoting effect may be mediated by the levels of the products of BCAT1/ECA39 activity, namely, branched-chain keto acids. Copyright (C) 1999 Federation of European Biochemical Societies.
| Original language | English |
|---|---|
| Pages (from-to) | 255-261 |
| Number of pages | 7 |
| Journal | FEBS Letters |
| Volume | 457 |
| Issue number | 2 |
| DOIs | |
| State | Published - 27 Aug 1999 |
Bibliographical note
Funding Information:We thank Dr. Shoshana Klein and Ittai Ben-Porath for critical reading of the manuscript and Dr. Ofra Yanuka for technical assistance. This research was supported by grant # 3811a from The Council For Tobacco Research, by grant # 93-00017 from the United States-Israel Binational Science Foundation (BSF), Jerusalem, Israel and by the Huruvitz Fund. FACS analysis was performed using equipment purchased by a grant from the Israel National Foundation.
Keywords
- Aminotransferase
- Apoptosis
- Branched-chain amino acid
- Keto acid