Track topics on Twitter Track topics that are important to you
In sporadic Alzheimer's disease (AD), neurofibrillary lesion formation is preceded by extensive post-translational modification of the microtubule associated protein tau. To identify the modification signature associated with tau lesion formation at single amino acid resolution, immunopurified paired helical filaments were isolated from AD brain and subjected to nanoflow liquid chromatography-tandem mass spectrometry analysis. The resulting spectra identified monomethylation of lysine residues as a new tau modification. The methyl-lysine was distributed among seven residues located in the projection and microtubule binding repeat regions of tau protein, with one site, K254, being a substrate for a competing lysine modification, ubiquitylation. To characterize methyl lysine content in intact tissue, hippocampal sections prepared from post mortem late-stage AD cases were subjected to double-label confocal fluorescence microscopy using anti-tau and anti-methyl lysine antibodies. Anti-methyl lysine immunoreactivity colocalized with 78 ± 13% of neurofibrillary tangles in these specimens. Together these data provide the first evidence that tau in neurofibrillary lesions is post-translationally modified by lysine methylation.
Greenebaum Cancer Center, University of Maryland, Baltimore, MD, 21201, USA.
This article was published in the following journal.
Name: Acta neuropathologica
DNA methylation is one of the most stable but dynamically regulated epigenetic marks that act as determinants of cell fates during embryonic development through regulation of various forms of gene exp...
There is increasing interest in DNA methylation studies in Alzheimer's disease (AD), but little is still known concerning the relationship between gene-promoter methylation and circulating biomarkers ...
Analyzing protein ubiquitylation changes during physiological or pathological processes is challenging due to its high reversibility and dynamic turnover of modified targets. We have developed a prote...
Pyrrolizidine alkaloids (PAs) are known hepatotoxins. The execution of the toxicities of the alkaloids requires metabolic activation. Protein modification by reactive metabolites of PAs has been sugge...
T3D-959, a dual PPAR-δ/PPAR γ nuclear receptor agonist and former diabetes drug candidate, has been repositioned as an Alzheimer's disease (AD)-modifying therapy.
This research study will assess whether AAB-001 is safe, well tolerated and effective for use in patients with Alzheimer's Disease. AAB-001 is a new drug that is not available outside thi...
The purpose of this study is to establish the parenteral lysine requirements for neonates.
Amino acids are the building blocks of the body's protein and are used to build muscle, body tissue, and to support the immune system. Amino acids play a crucial role in growth and develop...
The purpose of this study is to determine whether short-term use of the drugs ibuprofen and lovastatin affects levels of a protein called beta-amyloid in people who are at risk for develop...
The aim of this study is to measure the effect of EGb 761® versus placebo on the ratio of the isoform of the protein precursor of beta amyloid platelets, in patients with mild to moderate...
The specific patterns of POST-TRANSLATIONAL PROTEIN MODIFICATION of HISTONES, i.e. histone ACETYLATION; METHYLATION; PHOSPHORYLATION; and ubiquitination, at specific amino acid residues, that are involved in assembly, maintenance, and modification of different chromatin structural states, such as EUCHROMATIN and HETEROCHROMATIN.
An enzyme that catalyzes the methylation of the epsilon-amino group of lysine residues in proteins to yield epsilon mono-, di-, and trimethyllysine. EC 18.104.22.168.
A precursor to the AMYLOID BETA-PROTEIN (beta/A4). Alterations in the expression of the amyloid beta-protein precursor (ABPP) gene, located on chromosome 21, plays a role in the development of the neuropathology common to both ALZHEIMER DISEASE and DOWN SYNDROME. ABPP is associated with the extensive extracellular matrix secreted by neuronal cells. Upon cleavage, this precursor produces three proteins of varying amino acid lengths: 695, 751, and 770. The beta/A4 (695 amino acids) or beta-amyloid protein is the principal component of the extracellular amyloid in senile plaques found in ALZHEIMER DISEASE; DOWN SYNDROME and, to a limited extent, in normal aging.
Enzymes that are part of the restriction-modification systems. They are responsible for producing a species-characteristic methylation pattern, on either adenine or cytosine residues, in a specific short base sequence in the host cell's own DNA. This methylated sequence will occur many times in the host-cell DNA and remain intact for the lifetime of the cell. Any DNA from another species which gains entry into a living cell and lacks the characteristic methylation pattern will be recognized by the restriction endonucleases of similar specificity and destroyed by cleavage. Most have been studied in bacterial systems, but a few have been found in eukaryotic organisms.
Post-transcriptional biological modification of messenger, transfer, or ribosomal RNAs or their precursors. It includes cleavage, methylation, thiolation, isopentenylation, pseudouridine formation, conformational changes, and association with ribosomal protein.
Within medicine, nutrition (the study of food and the effect of its components on the body) has many different roles. Appropriate nutrition can help prevent certain diseases, or treat others. In critically ill patients, artificial feeding by tubes need t...