Histone acetyltransferases and deacetylase in Entamoeba histolytica.
In our efforts to understand how transcription may be regulated in Entamoeba histolytica, we have examined if this parasite has conserved enzymatic mechanisms for targeted acetylation and deacetylation of histones. Western blotting indicated that basic nuclear proteins in the size range of 16-23 kDa were acetylated in amebic trophozoites, suggesting histone acetylation. Single representatives of the GNAT and MYST family of histone acetyltransferases (HATs) were identified in the E. histolytica genome and their expression in amebic trophozoites was detected by reverse transcription of RNA followed by the polymerase chain reaction (RT-PCR). Full-length recombinant EhMYST protein demonstrated HAT activity with calf thymus histones and showed a preference for histone H4, similar to the yeast MYST protein, Esa1. However, ehMYST did not complement a yeast esa1 mutation. Histone deacetylase (HDAC) activity was detected in nuclear extracts from E. histolytica, and characteristically, was inhibited by trichostatin A (TSA). Consistent with the observation of HDAC activity, RT-PCR analysis demonstrated that an amebic hdac1 homolog (ehHDAC) is expressed and appropriately spliced in E. histolytica trophozoites. Our results suggest that mechanisms for histone acetylation and deacetylation are operational in E. histolytica.
Ramakrishnan
Girija
G
Department of Medicine, University of Virginia, Charlottesville, VA 22908, USA.
Gilchrist
Carol A
CA
Musa
Hussein
H
Torok
Michael S
MS
Grant
Patrick A
PA
Mann
Barbara J
BJ
Petri
William A
WA
D000107:Acetylation; D000123:Acetyltransferases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004748:Entamoeba histolytica / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017125:Genes, Protozoan; D005816:Genetic Complementation Test; D051548:Histone Acetyltransferases; D006655:Histone Deacetylases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D006657:Histones / Q000378:metabolism*; D006877:Hydroxamic Acids / Q000494:pharmacology; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D016053:RNA, Protozoan / Q000032:analysis; D017385:Sequence Homology; D014158:Transcription, Genetic; D015003:Yeasts / Q000235:genetics
D004791:Enzyme Inhibitors; D006657:Histones; D006877:Hydroxamic Acids; D015800:Protozoan Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan; C012589:trichostatin A; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; D006655:Histone Deacetylases