A transitory activation of protein kinase-A induces a sustained tau hyperphosphorylation at multiple sites in N2a cells-imply a new mechanism in Alzheimer pathology Authors
First Online: 09 February 2006 Received: 10 August 2005 Accepted: 23 October 2005 DOI:
Cite this article as: Zhang, Y., Li, H., Wang, D. et al. J Neural Transm (2006) 113: 1487. doi:10.1007/s00702-005-0421-2 Summary.
Overactivation of protein kinase in the end stage of Alzheimer’s disease brain has not been established. The purpose of the present study was to explore the possible mechanism for protein kinases in leading to Alzheimer-like tau hyperphosphorylation. We found that incubation of N2a/tau441 with forskolin, a specific activator of cAMP-dependent protein kinase (PKA), induced an increased phosphorylation level of tau at both PKA and non-PKA sites in a dose- and time-dependent manner, and the hyperphosphorylation of tau was positively correlated with the elevation of PKA activity. When the cells were transitorily incubated with forskolin, a temporary activation of PKA with a sustained and almost equally graded tau hyperphosphorylation at some non-PKA sites was observed. In either case, the activity of glycogen synthase kinase-3 (GSK-3) was not changed. It is suggested that only transitory activation of PKA in early stage of Alzheimer disease may result in a sustained tau hyperphosphorylation at multiple sites, implying a new mechanism to Alzheimer-like tau hyperphosphorylation.
Keywords: Alzheimer’s disease, tau, cAMP-dependent protein kinase, glycogen synthase kinase-3, abnormal hyperphosphorylation.
The first and second authors contributed equally to the paper
References Adashi, EY, Resnick, CE 1986 3′,5′-cyclic adenosine monophosphate as an intracellular second messenger of luteinizing hormone: application of the forskolin criteria J Cell Biochem 31 217 228 PubMed CrossRef Avila, J, Lucas, JJ, Perez, M, Hernandez, F 2004 Role of tau protein in both physiological and pathological conditions Physiol Rev 84 361 384 PubMed CrossRef Bennecib, M, Gong, CX, Grundke-Iqbal, I, Iqbal, K 2000 Role of protein phosphatase-2A and -1 in the regulation of GSK-3, cdk5 and cdc2 and the phosphorylation of tau in rat forebrain FEBS Lett 485 87 93 PubMed CrossRef Bhat, RV, Budd Haeberlein, SL, Avila, J 2004 Glycogen synthase kinase 3: a drug target for CNS therapies J Neurochem 89 1313 1317 PubMed CrossRef Biernat, J, Mandelkow, EM, Schroter, C, Lichtenberg-Kraag, B, Steiner, B, Berling, B, Meyer, H, Mercken, M, Vandermeeren, A, Goedert, M, et al. 1992 The switch of tau protein to an Alzheimer-like state includes the phosphorylation of two serine-proline motifs upstream of the microtubule binding region EMBO J 11 1593 1597 PubMed Braak, E, Braak, H, Mandelkow, EM 1994 A sequence of cytoskeleton changes related to the formation of neurofibrillary tangles and neuropil threads Acta Neuropathol (Berl) 87 554 567 Casnellie, JE 1991 Assay of protein kinases using peptides with basic residues for phosphocellulose binding Meth Enzymol 200 115 120 PubMed CrossRef Gong, CX, Liu, F, Grundke-Iqbal, I, Iqbal, K 2005 Post-translational modifications of tau protein in Alzheimer’s disease J Neural Transm 112 813 838 PubMed CrossRef Greenwood, JA, Scott, CW, Spreen, RC, Caputo, CB, Johnson, GV 1994 Casein kinase II preferentially phosphorylates human tau isoforms containing an amino-terminal insert. Identification of threonine 39 as the primary phosphate acceptor J Biol Chem 269 4373 4380 PubMed Grundke-Iqbal, I, Iqbal, K, Tung, YC, Quinlan, M, Wisniewski, HM, Binder, LI 1986 Abnormal phosphorylation of the microtubule-associated protein tau (tau) in Alzheimer cytoskeletal pathology Proc Natl Acad Sci USA 83 4913 4917 PubMed CrossRef Iqbal, K, Grundke-Iqbal, I, Zaidi, T, Merz, PA, Wen, GY, Shaikh, SS, Wisniewski, HM, Alafuzoff, I, Winblad, B 1986 Defective brain microtubule assembly in Alzheimer’s disease Lancet ii 421 426 CrossRef Iqbal, K, Alonso, A del C, El-Akkad, E, Gong, C-X, Haque, N, Khatoon, S, Pei, JJ, Tsujio, I, Wang, JZ, Grundke-Iqbal, I 2002 Significance and mechanism of Alzheimer neurofibrillary degeneration and therapeutic targets to inhibit this lesion J Mol Neurosci 19 95 99 PubMed Kemp, BE, Graves, DJ, Benjamini, E, Krebs, EG 1977 Role of multiple basic residues in determining the substrate specificity of cyclic AMP-dependent protein kinase J Biol Chem 252 4888 4894 PubMed Kopke, E, Tung, YC, Shaikh, S, Alonso, AC, Iqbal, K, Grundke-Iqbal, I 1993 Microtubule-associated protein tau. Abnormal phosphorylation of a non-paired helical filament pool in Alzheimer disease J Biol Chem 268 24374 24384 PubMed Kosik, KS 1992 Alzheimer’s disease: a cell biological perspective Science 256 780 783 PubMed Ksiezak-Reding, H, Binder, LI, Yen, SH 1988 Immunochemical and biochemical characterization of tau proteins in normal and Alzheimer’s disease brains with Alz 50 and Tau-1 J Biol Chem 263 7948 7953 PubMed Ksiezak-Reding, H, Binder, LI, Yen, SH 1990 Alzheimer disease proteins (A68) share epitopes with tau but show distinct biochemical properties J Neurosci Res 25 420 430 PubMed CrossRef Lau, LF, Schachter, JB, Seymour, PA, Sanner, MA 2002 Tau protein phosphorylation as a therapeutic target in Alzheimer’s disease Curr Top Med Chem 2 395 415 PubMed CrossRef Laurenza, A, Sutkowski, EM, Seamon, KB 1989 Forskolin: a specific stimulator of adenylyl cyclase or a diterpene with multiple sites of action? Trends Pharmacol Sci 10 442 447 PubMed CrossRef Lee, VM, Balin, BJ, Otvos, L, Jr, Trojanowski, JQ 1991 A68: a major subunit of paired helical filaments and derivatized forms of normal Tau Science 251 675 678 PubMed Liu, SJ, Zhang, AH, Li, HL, Wang, Q, Deng, HM, Netzer, WJ, Xu, H, Wang, JZ 2003 Overactivation of glycogen synthase kinase-3 by inhibition of phosphoinositol-3 kinase and protein kinase C leads to hyperphosphorylation of tau and impairment of spatial memory J Neurochem 87 1333 1344 PubMed CrossRef Liu, SJ, Zhang, JY, Li, HL, Fang, ZY, Wang, Q, Deng, HM, Gong, CX, Grundke-Iqbal, I, Iqbal, K, Wang, JZ 2004 Tau becomes a more favorable substrate for GSK-3 when it is prephosphorylated by PKA in rat brain J Biol Chem 279 50078 50088 PubMed CrossRef Morishima-Kawashima, M, Hasegawa, M, Takio, K, Suzuki, M, Yoshida, H, Watanabe, A, Titani, K, Ihara, Y 1995 Hyperphosphorylation of tau in PHF Neurobiol Aging 16 365 380 PubMed CrossRef Pei, JJ, Tanaka, T, Tung, YC, Braak, E, Iqbal, K, Grundke-Iqbal, I 1997 Distribution, levels, and activity of glycogen synthase kinase-3 in the Alzheimer disease brain J Neuropathol Exp Neurol 56 70 78 PubMed Singh, TJ, Zaidi, T, Grundke-Iqbal, I, Iqbal, K 1996 Non-proline-dependent protein kinases phosphorylate several sites found in tau from Alzheimer disease brain Mol Cell Biochem 154 143 151 PubMed CrossRef Sun, L, Liu, SY, Zhou, XW, Wang, XC, Liu, R, Wang, Q, Wang, JZ 2003 Inhibition of protein phosphatase 2A- and protein phosphatase 1-induced tau hyperphosphorylation and impairment of spatial memory retention in rats Neurosci 118 1175 1182 CrossRef Sun, L, Wang, X, Liu, S, Wang, Q, Wang, J, Bennecib, M, Gong, CX, Sengupta, A, Grundke-Iqbal, I, Iqbal, K 2005 Bilateral injection of isoproterenol into hippocampus induces Alzheimer-like hyperphosphorylation of tau and spatial memory deficit in rat FEBS Lett 579 251 258 PubMed CrossRef Tanaka, T, Zhong, J, Iqbal, K, Trenkner, E, Grundke-Iqbal, I 1998 The regulation of phosphorylation of tau in SY5Y neuroblastoma cells: the role of protein phosphatases FEBS Lett 426 248 254 PubMed CrossRef Tolnay, M, Probst, A 1999 Tau protein pathology in Alzheimer’s disease and related disorders Neuropathol Appl Neurobiol 25 171 187 PubMed CrossRef Tsujio, I, Tanaka, T, Kudo, T, Nishikawa, T, Shinozaki, K, Grundke-Iqbal, I, Iqbal, K, Takeda, M 2000 Inactivation of glycogen synthase kinase-3 by protein kinase C delta: implications for regulation of tau phosphorylation FEBS Lett 469 111 117 PubMed CrossRef Wang, JZ, Wu, Q, Smith, A, Grundke-Iqbal, I, Iqbal, K 1998 Tau is phosphorylated by GSK-3 at several sites found in Alzheimer disease and its biological activity markedly inhibited only after it is prephosphorylated by A-kinase FEBS Lett 436 28 34 PubMed CrossRef Wang, XC, Hu, ZH, Tang, XW, Wu, YG, Wang, JZ 2004 Correlation of Alzheimer-like tau abnormal hyperphosphorylation and fMRI BOLD signal intensity J Curr Alz Res 1 143 145 CrossRef Weingarten, MD, Lockwood, AH, Hwo, SY, Kirschner, MW 1975 A protein factor essential for microtubule assembly Proc Natl Acad Sci USA 72 1858 1862 PubMed CrossRef