Establishment of the enzymatic protein acetylation independent of acetyl CoA: recombinant glutathione S-transferase 3-3 is acetylated by a novel membrane-bound transacetylase using 7,8-diacetoxy-4-methyl coumarin as the acetyl donor.
The current knowledge on biological protein acetylation is confined to acetyl CoA-dependent acetylation of protein catalyzed by specific acetyl transferases and the non-enzymatic acetylation of protein by acetylated xenobiotics such as aspirin. We have discovered a membrane-bound enzyme catalyzing the transfer of acetyl groups from the acetyl donor 7,8-diacetoxy-4-methyl coumarin (DAMC) to glutathione S-transferase 3-3 (GST3-3), termed DAMC:protein transacetylase (TAase). The purified enzyme was incubated with recombinant GST3-3 subunit and DAMC, the modified protein was isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in gel digested with trypsin and the tryptic digest was analyzed by mass spectrometry. The N-terminus and six lysines, Lys-51, -82, -124, -181, -191 and -210, were found to be acetylated. The acetylation of GST3-3 described above was not observed in the absence of either DAMC or TAase. These results clearly establish the phenomenon of protein acetylation independent of acetyl CoA catalyzed by a hitherto unknown enzyme (TAase) utilizing a certain xenobiotic acetate (DAMC) as the active acetyl donor.
Kohli
Ekta
E
Department of Biochemistry, V.P. Chest Institute, University of Delhi, India.
Gaspari
Marco
M
Raj
Hanumantharao G
HG
Parmar
Virinder S
VS
van der Greef
Jan
J
Gupta
Garima
G
Kumari
Ranju
R
Prasad
Ashok K
AK
Goel
Sanjay
S
Pal
Giridhari
G
Tyagi
Yogesh K
YK
Jain
Subhash C
SC
Ahmad
Nizamuddin
N
Watterson
Arthur C
AC
Olsen
Carl E
CE
D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000107:Acetylation; D000115:Acetylesterase / Q000378:metabolism*; D003374:Coumarins / Q000737:chemistry*; D005982:Glutathione Transferase / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
C114369:7,8-diacetoxy-4-methylcoumarin; D003374:Coumarins; D011994:Recombinant Proteins; D000105:Acetyl Coenzyme A; D005982:Glutathione Transferase; D000115:Acetylesterase