Tau Proteins:

Tau is a microtubule-associated protein, encoded by the MAPT gene, that stabilizes axonal microtubules. In Alzheimer’s disease and the primary tauopathies, Tau becomes hyperphosphorylated, detaches from microtubules and aggregates into paired helical filaments and neurofibrillary tangles. Isoform composition differs by disease: Alzheimer’s tangles contain both 3R and 4R Tau, Pick’s disease is predominantly 3R, and progressive supranuclear palsy and corticobasal degeneration are predominantly 4R. Tangle burden tracks cognitive decline more closely than amyloid plaque load, and phosphorylated Tau species such as p-tau181 and p-tau217, measured in CSF and plasma, are now used as biomarkers of Alzheimer’s pathology. Isoform-defined Tau proteins and site-specific Tau antibodies are therefore core reagents for studying disease mechanisms, building biomarker assays and screening Tau-targeted therapies.

All six CNS isoforms (2N4R/Tau-441, 1N4R/Tau-412, 0N4R/Tau-383, 2N3R/Tau-410, 1N3R/Tau-381, 0N3R/Tau-352) plus PNS-Tau (Big Tau). HEK293-expressed C-Myc/DDK-tagged proteins are available for every isoform at >90% purity; E. coli-expressed His-tagged proteins are available for every isoform and PNS-Tau, and HEK293 over-expression lysates cover most isoforms.

Use HEK293-expressed Tau when post-translational modifications matter: evaluating PTM-sensitive antibodies, studying proteoforms or interactions, or comparing how the expression host affects aggregation, microtubule binding and filament formation. E. coli-expressed Tau suits routine applications and serves as an unmodified reference.

PNS-Tau is the high-molecular-weight isoform expressed in peripheral neurons. It carries the exon 4a-encoded insert in the N-terminal projection domain. OriGene supplies it as purified HEK293 protein (TP316166, >90%), purified E. coli protein (TP750316, >80%), an over-expression lysate (LY413820), a CytoSection control (TS416166P5) and expression clones.

No reactivity with full-length Tau was observed in indirect ELISA. TA592997 (Ac-K281) and TA592889 (Ac-K274) gave dose-dependent signal on their acetylated peptides from 0.15 to 10 ng/mL and no signal on full-length Tau protein. Six rabbit monoclonals cover K274 and K281.

7 antibodies target pT217 and 5 target pT181, most of them ELISA-tested. Sandwich ELISA data are available for capture clones 4C1 (TA600576, pT181) and 1A9 (TA600577, pT217), each paired with detection antibody 9A5 (TA700576).

7 antibodies list IHC as a tested application: TA424093 (p(Ser214)), TA422607 (p(Ser396)), TA378338 (p(Ser416)), TA422586 (p(Thr231)), TA809192 (total Tau), TA809201 (total Tau), UM800131 (total Tau).

CytoSections are fixed, paraffin-embedded cell blocks prepared from cells expressing a single Tau isoform. Use them as positive and negative controls when validating antibodies for IHC, IF and ICC. Five are available: PNS-Tau, 2N4R, 0N4R, 1N4R and 0N3R.

Contact the OriGene team with the isoform, mutations, tag, expression host and quantity you need, and they will follow up on your project.