| 240-KDA PROTEASOME INHIBITOR (CF-2) IS IDENTICAL TO DELTA-AMINOLEVULINIC-ACID DEHYDRATASE |
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| Author(s): GUO GG, GU MZ, ETLINGER JD |
| Source: JOURNAL OF BIOLOGICAL CHEMISTRY Volume: 269 Issue: 17 Pages: 12399-12402 Published: APR 29 1994 |
| Times Cited: 59 References: 32 |
| Abstract: The 240-kDa proteasome inhibitor has been reported to be an ATP-stabilized component (CF-2) of the 26 S proteasome complex. We now report that this inhibitory factor is indistinguishable from delta-aminolevulinic acid dehydratase (ALAD), the second enzyme in the pathway of heme synthesis, based upon the following observations: 1) common sequence of the first 14 N-terminal amino acids; 2) identical migration on native and SDS-polyacrylamide gel electrophoresis; 3) identical isoelectric points of pH 7.1; 4) cross-reactivity of specific polyclonal antibodies; 5) similar dehydratase and proteasome inhibitor specific activities in both proteins; and 6) the presence of both activities in recombinant ALAD. The dual role of this protein as CF-2 in the ATP/ ubiquitin-dependent pathway and in heme synthesis may be an example of ''gene sharing'' and explains the unexpected abundance of ALAD noted in earlier studies. |
| Document Type: Note |
| Language: English |
Addresses:
1. NEW YORK MED COLL, DEPT CELL BIOL & ANAT, VALHALLA, NY 10595 USA
2. SUNY HLTH SCI CTR, DEPT ANAT & CELL BIOL, BROOKLYN, NY 11203 USA |
| Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC, 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 |
| Subject Category: Biochemistry & Molecular Biology |
| IDS Number: NH716 |
| ISSN: 0021-9258 |