Filamen PH: Perbedaan antara revisi
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Hiperfosforilasi terjadi karena terjadi kerusakan transduksi sinyal selular yang disebabkan oleh tidak seimbangnya aktivitas [[protein]] dari beberapa [[enzim]] [[kinase]] dan [[fosfatase]].<ref name="PM20553310" /> |
Hiperfosforilasi terjadi karena terjadi kerusakan transduksi sinyal selular yang disebabkan oleh tidak seimbangnya aktivitas [[protein]] dari beberapa [[enzim]] [[kinase]] dan [[fosfatase]].<ref name="PM20553310" /> Proses kimiawi ini dapat diredam dengan meningkatkan aktivitas [[enzim]] [[fosfoseril protein fosfatase]]<ref>{{en}}{{cite web |
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| url = http://www.ncbi.nlm.nih.gov/pubmed/15270196 |
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| title = Inhibition of neurofibrillary degeneration: a promising approach to Alzheimer's disease and other tauopathies |
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| accessdate = 2010-06-21 |
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| work = Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities; Iqbal K, Grundke-Iqbal I. |
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}}</ref> dan [[fosfotreonil protein fosfatase]].<ref>{{en}}{{cite web |
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| url = http://www.ncbi.nlm.nih.gov/pubmed/10961432 |
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| title = Mechanism of neurofibrillary degeneration and pharmacologic therapeutic approach |
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| accessdate = 2010-06-21 |
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| work = New York State Institute for Basic Research in Developmental Disabilities; Iqbal K, Alonso AD, Gondal JA, Gong CX, Haque N, Khatoon S, Sengupta A, Wang JZ, Grundke-Iqbal I. |
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Activities of phosphoseryl/phosphothreonyl protein phosphatases (PP)-2A and PP-1 which can dephosphorylate the abnormal tau to a normal-like state are compromised in AD brain. Dephosphorylation by PP-2A and PP-2B and to a lesser extent by PP-1 restores the normal microtubule assembly promoting activity in AD P-tau in vitro. Neurofibrillary tangles of PHF isolated from AD brain are also dissociated on in vitro dephosphorylation with PP-2A, and the tau released by this treatment can stimulate microtubule assembly. Thus, it appears that the abnormal hyperphosphorylation of tau leads to neurodegeneration through breakdown of the microtubule network and that the abnormal tau on association with normal tau forms neurofibrillary tangles of tau filaments i.e. PHF/SF. Increase in tau phosphatase activity is a promising approach to inhibit neurofibrillary degeneration and thereby the diseases characterized by this lesion. |
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==Rujukan== |
==Rujukan== |
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Revisi per 21 Juni 2010 13.09
Filamen PH (bahasa Inggris: neurofibrillary tangle, paired helical filaments, PHF) adalah tumpukan protein yang ditemukan di dalam neuron penderita Alzheimer, pertama kali oleh Alois Alzheimer.
Filamen ini terbentuk karena protein tau - sebuah protein yang berperan dalam perakitan dan pemeliharaan struktur mikrotubula - mengalami hiperfosforilasi sehingga memecahkan struktur mikrotubula. Radikal protein tau, kemudian berhimpun menjadi filamen PH.[1]
Hiperfosforilasi terjadi karena terjadi kerusakan transduksi sinyal selular yang disebabkan oleh tidak seimbangnya aktivitas protein dari beberapa enzim kinase dan fosfatase.[1] Proses kimiawi ini dapat diredam dengan meningkatkan aktivitas enzim fosfoseril protein fosfatase[2] dan fosfotreonil protein fosfatase.[3]
Activities of phosphoseryl/phosphothreonyl protein phosphatases (PP)-2A and PP-1 which can dephosphorylate the abnormal tau to a normal-like state are compromised in AD brain. Dephosphorylation by PP-2A and PP-2B and to a lesser extent by PP-1 restores the normal microtubule assembly promoting activity in AD P-tau in vitro. Neurofibrillary tangles of PHF isolated from AD brain are also dissociated on in vitro dephosphorylation with PP-2A, and the tau released by this treatment can stimulate microtubule assembly. Thus, it appears that the abnormal hyperphosphorylation of tau leads to neurodegeneration through breakdown of the microtubule network and that the abnormal tau on association with normal tau forms neurofibrillary tangles of tau filaments i.e. PHF/SF. Increase in tau phosphatase activity is a promising approach to inhibit neurofibrillary degeneration and thereby the diseases characterized by this lesion.
Rujukan
- ^ a b (Inggris)"The Role of Tau in Alzheimer's Disease and Related Disorders". Department of Neurobiology and Behavior and Institute for Memory Impairments and Neurological Disorders, University of California; Medeiros R, Baglietto-Vargas D, Laferla FM. Diakses tanggal 2010-06-21.
- ^ (Inggris)"Inhibition of neurofibrillary degeneration: a promising approach to Alzheimer's disease and other tauopathies". Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities; Iqbal K, Grundke-Iqbal I. Diakses tanggal 2010-06-21.
- ^ (Inggris)"Mechanism of neurofibrillary degeneration and pharmacologic therapeutic approach". New York State Institute for Basic Research in Developmental Disabilities; Iqbal K, Alonso AD, Gondal JA, Gong CX, Haque N, Khatoon S, Sengupta A, Wang JZ, Grundke-Iqbal I. Diakses tanggal 2010-06-21.