Senescence marker protein-30 as a novel antiaging molecule.
Senescence marker protein-30 (SMP30), composed of 299 amino acids, has an approximate molecular mass of 32-34 kDa and has a pI 4.9 in charge. The amino acid alignment from various animal species revealed a highly conserved structure. SMP30 has an enzyme activity hydrolyzing sarin, soman, and tabun, known as lethal toxic nerve chemicals. We analyzed the organophosphatase activity of SMP30 using DFP as a substrate. This DFPase activity is revealed in a dose-dependent manner in the presence of magnesium ions. We investigated the intracellular localization of SMP30. It is localized in both the cytoplasm and nucleus. To confirm the presence of SMP30 in the nucleus, we prepared nuclear and cytoplasmic extracts from isolated cultured hepatocytes. Western blotting showed that SMP30 was detected in both extracts. Because the expression is reduced by carbon tetrachloride, one can speculate that the expression is modulated by oxidative stress increased with aging.
Feng
Dongyun
D
Department of Molecular Pathology, Tokyo Metropolitan Institute of Gerontology, Tokyo 173-0015, Japan.
Kondo
Yoshitaka
Y
Ishigami
Akihito
A
Kuramoto
Masashi
M
Machida
Takeo
T
Maruyama
Naoki
N
D000375:Aging; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D002251:Carbon Tetrachloride / Q000494:pharmacology; D002467:Cell Nucleus / Q000378:metabolism; D016922:Cellular Senescence; D003593:Cytoplasm / Q000378:metabolism; D019143:Evolution, Molecular; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D047908:Intracellular Signaling Peptides and Proteins; D018384:Oxidative Stress; D010766:Phosphorylation; D010802:Phylogeny; D017382:Reactive Oxygen Species; D015238:Sulfotransferases
D002135:Calcium-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; C513323:RGN protein, human; D017382:Reactive Oxygen Species; D002251:Carbon Tetrachloride; D015238:Sulfotransferases; C028152:alcohol sulfotransferase