Characterization of ARD1 variants in mammalian cells.
Mouse ARD1 (mARD1) has been reported to negatively regulate the hypoxia-inducible factor 1alpha (HIF-1alpha) protein by acetylating a lysine residue and enhancing HIF-1alpha ubiquitination and degradation. However, it was recently reported that human ARD1 (hARD1) does not affect HIF-1alpha stability. To further explore the activities of the two orthologs, three mouse (mARD1(198), mARD1(225), mARD1(235)) and two human (hARD1(131), hARD1(235)) variants were identified and characterized. Among these, mARD1(225) was previously reported as a novel negative regulator of HIF-1alpha. Amino acid sequence analysis showed that the C-terminal region (aa 158-225) of mARD1(225) completely differs from those of mouse and human ARD1(235), although all three proteins share a well-conserved N-acetyltransferase domain (aa 45-130). The effects of ARD1 variants were evaluated with respect to HIF-1alpha stability and acetylation activity. Interestingly, mARD1(225) strongly decreased the level of HIF-1alpha and increased the extent of acetylation, whereas mARD1(235) and hARD1(235) variants had a much weaker effect on HIF-1alpha stability and acetylation. These results suggest that ARD1 variants might have different effects on HIF-1alpha stability and acetylation, which may reflect diverse biological functions that remain to be determined.
Kim
Se-Hee
SH
Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 151-742, Republic of Korea.
Park
Jeong Ae
JA
Kim
Jin Hyoung
JH
Lee
Ji-Won
JW
Seo
Ji Hae
JH
Jung
Bo-Kyung
BK
Chun
Kwang-Hoon
KH
Jeong
Joo-Won
JW
Bae
Moon-Kyoung
MK
Kim
Kyu-Won
KW
D000107:Acetylation; D000123:Acetyltransferases / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001191:Arylamine N-Acetyltransferase / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D045744:Cell Line, Tumor; D006367:HeLa Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D063209:N-Terminal Acetyltransferase A; D063213:N-Terminal Acetyltransferase E; D041681:NIH 3T3 Cells; D020871:RNA Stability / Q000502:physiology; D017386:Sequence Homology, Amino Acid
C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007527:Isoenzymes; D000123:Acetyltransferases; D063209:N-Terminal Acetyltransferase A; C504824:NAA10 protein, human; C508558:Naa10 protein, mouse; D063213:N-Terminal Acetyltransferase E; D001191:Arylamine N-Acetyltransferase; C089384:N-acetyltransferase 1