Structure and Function of full-lenght Tau

Tau protein, encoded by the MAPT gene, is a microtubule-associated protein involved in the regulation of microtubule stability in neurons, contributing to cell shape maintenance and intracellular transport, among other functions. Tau is not found as an unique isoform; instead, different tau isoforms of varying sizes are present in the brain but never a full-length tau isoform (Full Tau) containing all its 16 exons has been previously found.

This study has explored the structure and function of the full tau isoform, which includes all exons of the MAPT gene. To achieve this, we expressed the full tau isoform in bacteria, alongside the tau 42 isoform as a control and tested its microtubule-binding capacity, self-aggregation propensity, and effects on cultured cells, regarding cell proliferation and cell death. Our results have indicated several differences between the full tau and tau 42 isoforms, suggesting distinct roles in cellular dynamics. To explain those differences, we suggest the role of exon 8, which is present in the full tau isoform but absent in tau 42.