Filamen PH

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Filamen PH (bahasa Inggris: neurofibrillary tangle, paired helical filaments, PHF) adalah tumpukan protein yang ditemukan pertama kali oleh Alois Alzheimer di dalam neuron penderita Alzheimer.

Filamen ini terbentuk dari berbagai isomer[1] protein tau[2] - sebuah protein yang berperan dalam perakitan dan pemeliharaan struktur mikrotubula - mengalami hiperfosforilasi sehingga memecahkan struktur mikrotubula. Radikal protein tau kemudian berhimpun menjadi filamen PH di dalam soma.[3]

Hiperfosforilasi terjadi karena terjadi kerusakan transduksi sinyal selular yang disebabkan oleh tidak seimbangnya aktivitas protein dari beberapa enzim fosfatase dan kinase,[3] seperti calmodulin-dependent protein kinase II, glycogen synthase kinase-3beta dan cyclin-dependent protein kinase 5.[4][5] Proses kimiawi ini dapat diredam dengan meningkatkan aktivitas enzim fosfoseril protein fosfatase[6] dan fosfotreonil protein fosfatase.[7]

Rujukan[sunting | sunting sumber]

  1. ^ (Inggris)"Multiple isoforms of human microtubule-associated protein tau: sequences and localization in neurofibrillary tangles of Alzheimer's disease". Medical Research Council, Laboratory of Molecular Biology, Cambridge, England; Goedert M, Spillantini MG, Jakes R, Rutherford D, Crowther RA. Diakses 2010-06-27. 
  2. ^ (Inggris)"Cloning and sequencing of the cDNA encoding a core protein of the paired helical filament of Alzheimer disease: identification as the microtubule-associated protein tau". Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom; Goedert M, Wischik CM, Crowther RA, Walker JE, Klug A. Diakses 2010-06-27. 
  3. ^ 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 2010-06-21. 
  4. ^ (Inggris)"Alzheimer neurofibrillary degeneration: significance, etiopathogenesis, therapeutics and prevention". Department of Neurochemistry New York State Institute for Basic Research in Developmental Disabilities; Iqbal K, Grundke-Iqbal I. Diakses 2010-06-21. 
  5. ^ (Inggris)"Kinases and phosphatases and tau sites involved in Alzheimer neurofibrillary degeneration". Pathophysiology Department, Tongji Medical College, Huazhong University of Science & Technology; Wang JZ, Grundke-Iqbal I, Iqbal K. Diakses 2010-06-21. 
  6. ^ (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 2010-06-21. 
  7. ^ (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 2010-06-21.