Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P10636 (tau protein)
 5,110 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tauopathies have been associated with Alzheimer's disease (AD), which frequently manifests together with diabetes mellitus type 2. Calcium-binding proteins such as the recently identified secretagogin (SCGN) might exert protective effects. As pancreatic beta-cells and neurons share common electrophysiological properties, we investigated the appearance of TAU (listed as MAPT in the HUGO and MGI Databases) protein at the islets of Langerhans and beta-cell-derived cell lines which highly express the neuroendocrine-specific protein SCGN. Six predominant TAU isoforms could be identified by immunoblotting, which formed TAU deposits detectable by immunofluorescence and sarkosyl-insoluble pellets. Using GST-SCGN pull-down assays, a calcium-dependent SCGN-TAU interaction was found. In this line, sucrose density gradient fractionation and differential ultracentrifugation studies of TAU and SCGN revealed co-appearance of both proteins. Co-localization of TAU and SCGN within insulinoma cells and islets of Langerhans mainly restricted to insulin-positive beta-cells was demonstrated by confocal microscopy. Motivated by these findings, we looked if SCGN overexpression could exert protective function on Rin-5F cells, which showed differences in TAU levels. Testing the vulnerability of Rin-5F clones by MTT assay, we revealed that high TAU levels going along with highest TAU aggregates could not be antagonized by high levels of SCGN protein. Our findings demonstrated for the first time the association of TAU and the calcium-binding protein SCGN and support earlier results implicating that beta-cells might represent an extra cerebral site of tauopathy.
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PMID:Expression of TAU in insulin-secreting cells and its interaction with the calcium-binding protein secretagogin. 2006 14

Neuropathological features in Alzheimer's Disease (AD) include the presence of hyperphosphorylated forms of the microtubule-associated tau protein (tau) in hippocampal neurones. Numerous studies indicate a neuroprotective effect of calcium-binding proteins (Ca2+ binding proteins) in neurodegenerative diseases (e.g., AD). Secretagogin is a newly described Ca2+ binding protein that is produced by pyramidal neurones of the human hippocampus. Recently, secretagogin expressing hippocampal neurones were demonstrated to resist tau-induced pathology in AD in contrast to the majority of neighbouring neurones. This suggested a neuroprotective effect of secretagogin in hippocampal neurones. Here, we investigated secretagogin expression in wild type (wt) mice as well as in hemizygous and homozygous P301L tau transgenic (tg) mice, which show pronounced and widespread tau pathology in hippocampal neurones. Secretagogin expression was analyzed at the immunohistochemical and biochemical levels in brains of age-matched wt and hemi- and homozygous tau tg mice. In wt mice hippocampal secretagogin-immunoreactive neurones were invariably detected, while immunoreactivity was much lower (P < 0.001) in tau tg mice. Of note, hippocampal secretagogin immunoreactivity was absent in 62.5% of homozygous tau tg mice. In line with this finding, Western blot analysis demonstrated a significant reduction in protein expression levels of secretagogin in homozygous tau tg compared to wt mice. Our results suggest that increased levels of tau negatively influence secretagogin expression in the hippocampus of tau tg mice.
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PMID:Reduced secretagogin expression in the hippocampus of P301L tau transgenic mice. 2144 54