Neuropathy target esterase.
نویسنده
چکیده
Neuropathy target esterase (NTE) is an integral membrane protein present in all neurons and in some non-neural-cell types of vertebrates. Recent data indicate that NTE is involved in a cell-signalling pathway controlling interactions between neurons and accessory glial cells in the developing nervous system. NTE has serine esterase activity and efficiently catalyses the hydrolysis of phenyl valerate (PV) in vitro, but its physiological substrate is unknown. By sequence analysis NTE has been found to be related neither to the major serine esterase family, which includes acetylcholinesterase, nor to any other known serine hydrolases. NTE comprises at least two functional domains: an N-terminal putative regulatory domain and a C-terminal effector domain which contains the esterase activity and is, in part, conserved in proteins found in bacteria, yeast, nematodes and insects. NTE's effector domain contains three predicted transmembrane segments, and the active-site serine residue lies at the centre of one of these segments. The isolated recombinant domain shows PV hydrolase activity only when incorporated into phospholipid liposomes. NTE's esterase activity appears to be largely redundant in adult vertebrates, but organophosphates which react with NTE in vivo initiate unknown events which lead, after a delay of 1-3 weeks, to a neuropathy with degeneration of long axons. These neuropathic organophosphates leave a negatively charged group covalently attached to the active-site serine residue, and it is suggested that this may cause a toxic gain of function in NTE.
منابع مشابه
Effect of vitamins B1, B6 and B12 (Neurobion) on diisopropylfluorophosphate–induced delayed neuropathy in mice
Certain organophosphorus esters such as diisopropylfluorophosphate (DFP) cause delayed neuropathy by inhibition of neuropathy target esterase (NTE) keeping neuron in normal function. In this study, effects of neurobion alone and in combination with dexamethasone on DFP–induced delayed neuropathy were evaluated. Thirty-five mice were divided to five groups that each group consists 7 mice. Except...
متن کاملEffect of vitamins B1, B6 and B12 (Neurobion) on diisopropylfluorophosphate–induced delayed neuropathy in mice
Certain organophosphorus esters such as diisopropylfluorophosphate (DFP) cause delayed neuropathy by inhibition of neuropathy target esterase (NTE) keeping neuron in normal function. In this study, effects of neurobion alone and in combination with dexamethasone on DFP–induced delayed neuropathy were evaluated. Thirty-five mice were divided to five groups that each group consists 7 mice. Except...
متن کاملCorrelation of neuropathy target esterase activity with specific tritiated di-isopropyl phosphorofluoridate-labelled proteins.
Neuropathy target esterase (NTE) is a membrane-bound carboxylesterase activity that has been proposed as the target site for initiation of organophosphate-induced delayed neuropathy. This activity is identified by its resistance to treatment with Paraoxon and sensitivity to co-incubation with Paraoxon and Mipafox. Sucrose-density-gradient centrifugation of membrane-associated proteins isolated ...
متن کاملAxonal degeneration and neuropathy target esterase.
This brief review summarizes recent observations which suggest a possible mechanism for organophosphate-induced delayed neuropathy (OPIDN). Neuropathy target esterase (NTE) has been shown to deacylate endoplasmic reticulum (ER) membrane phosphatidylcholine (PtdCho). Raised levels of PtdCho are present in the brains of Swiss cheese/NTE mutant Drosophila together with abnormal membrane structures...
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ورودعنوان ژورنال:
- The Biochemical journal
دوره 344 Pt 3 شماره
صفحات -
تاریخ انتشار 1999