Biomaterial Database

Activation of mitogen-activated protein kinase cascade and phosphorylation of cytoskeletal proteins after neurone-specific activation of p21ras. I. Mitogen-activated protein kinase cascade. 2001

M Holzer, and U Gärtner, and F J Klinz, and F Narz, and R Heumann, and T Arendt

Paul Flechsig Institute of Brain Research, Department of Neuroanatomy, University of Leipzig, Germany. holm@medizin.uni-leipzig.de

Alterations in the phosphorylation state of the microtubule-associated protein tau have been associated with the pathogenesis of neurofibrillary degeneration as well as with a neuroprotective action against apoptotic cell death. Mitogen-activated protein kinases (MAPK) phosphorylate tau protein in vitro but the pathophysiological significance of this tau phosphorylation and its effects on neuronal viability is far from clear. Moreover, an in vivo model of activation of MAPK, a key candidate for in vivo tau phosphorylation, is still lacking. The aim of the present study and the accompanying paper was to establish an animal model of stimulated MAPK and to analyse the consequences on tau phosphorylation and the neuronal cytoskeleton. We took advantage of transgenic mice with neurone-specific expression of activated ras protein (p21H-ras(Val12)). The expression of the transgene in these animals is forced to a subset of neurones by the use of the synapsin I promoter. Activity of B-raf was elevated by 37%, while activity of MAPK (ERK1/ERK2) was increased by 25% associated with a subcellular redistribution from the cytoplasmic to the nuclear compartment. Kinases downstream of MAPK such as p90rsk and glycogen synthase kinase 3beta were only marginally affected. Activity of p70S6 kinase was unaltered. The present model might be useful to study the effects of activation of the MAPK cascade on tau phosphorylation and its cell biological sequelae.

UI	MeSH Term	Description	Entries
D008822	Mice, Transgenic	Laboratory mice that have been produced from a genetically manipulated EGG or EMBRYO, MAMMALIAN.	Transgenic Mice,Founder Mice, Transgenic,Mouse, Founder, Transgenic,Mouse, Transgenic,Mice, Transgenic Founder,Transgenic Founder Mice,Transgenic Mouse
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D010744	Phosphoric Monoester Hydrolases	A group of hydrolases which catalyze the hydrolysis of monophosphoric esters with the production of one mole of orthophosphate.	Phosphatase,Phosphatases,Phosphohydrolase,Phosphohydrolases,Phosphomonoesterase,Phosphomonoesterases,Phosphoric Monoester Hydrolase,Hydrolase, Phosphoric Monoester,Hydrolases, Phosphoric Monoester,Monoester Hydrolase, Phosphoric
D010766	Phosphorylation	The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.	Phosphorylations
D003598	Cytoskeletal Proteins	Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.	Proteins, Cytoskeletal
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D016283	Proto-Oncogene Proteins p21(ras)	Cellular proteins encoded by the H-ras, K-ras and N-ras genes. The proteins have GTPase activity and are involved in signal transduction as monomeric GTP-binding proteins. Elevated levels of p21 c-ras have been associated with neoplasia. This enzyme was formerly listed as EC 3.6.1.47.	Proto-Oncogene Proteins c-ras,c-Ha-ras p21,c-Ki-ras p21,p21(N-ras),p21(c-Ha-ras),p21(c-Ki-ras),p21(c-ras),p21(ras),ras Proto-Oncogene Protein p21,Proto-Oncogene Protein p21(c-Ha-ras),Proto-Oncogene Protein p21(c-Ki-ras),Proto-Oncogene Protein p21(c-N-ras),Proto-Oncogene Protein p21(ras),Proto-Oncogene Protein ras,c-ras Proteins,p21 c-H-ras,p21 c-Ha-ras,p21 c-K-ras,p21 c-Ki-ras,p21 c-ras,ras Proto-Oncogene Product p21,Proteins c-ras, Proto-Oncogene,Proto Oncogene Protein ras,Proto Oncogene Proteins c ras,c Ha ras p21,c Ki ras p21,c ras Proteins,c-H-ras, p21,c-Ha-ras, p21,c-K-ras, p21,c-Ki-ras, p21,c-ras, Proto-Oncogene Proteins,c-ras, p21,p21 c H ras,p21 c Ha ras,p21 c K ras,p21 c Ki ras,p21 c ras,p21, c-Ha-ras,p21, c-Ki-ras,ras Proto Oncogene Product p21,ras Proto Oncogene Protein p21,ras, Proto-Oncogene Protein
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus
D020928	Mitogen-Activated Protein Kinases	A superfamily of PROTEIN SERINE-THREONINE KINASES that are activated by diverse stimuli via protein kinase cascades. They are the final components of the cascades, activated by phosphorylation by MITOGEN-ACTIVATED PROTEIN KINASE KINASES, which in turn are activated by mitogen-activated protein kinase kinase kinases (MAP KINASE KINASE KINASES).	Mitogen Activated Protein Kinase,Mitogen-Activated Protein Kinase,Kinase, Mitogen-Activated Protein,Kinases, Mitogen-Activated Protein,Mitogen Activated Protein Kinases,Protein Kinase, Mitogen-Activated,Protein Kinases, Mitogen-Activated