Facilitation of SUMO (small ubiquitin‐like modifier) modification at tau 340‐lys residue (a microtubule‐associated protein) through phosphorylation at 214‐ser residue

Abstract

Tau plays a role in numerous neuronal processes, such as vesicle transport, microtubule‐plasma membrane interaction and intracellular localization of proteins. SUMO (Small Ubiquitin‐like Modifier) modification (SUMOylation) appears to regulate diverse cellular processes including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin‐dependent degradation, as well as gene transcription. We noticed that putative SUMOylation site is localized at 340K of Tau (³³⁹VKSE³⁴²) with the consensus sequence information (FKxE; where F represents L, I, V or F and x is any amino acid). In this report, we demonstrated that ³⁴⁰K of Tau is the SUMOylation site and that a point mutant of Tau S214E (an analog of the phospho ²¹⁴S Tau) promotes its SUMOylation at ³⁴⁰Kand its nuclear or nuclear vicinity localization, by co‐immunoprecipitation and confocal microscopy analysis. Further, we demonstrate that the Tau S214E (neither Tau S214A nor Tau K340R) mutant increases its protein stability. However, the SUMOylation at ³⁴⁰K of Tau did not influence cell survival, as determined by FACS analysis. Therefore, our results suggested that the phosphorylation of Tau on ²¹⁴S residue promotes its SUMOylation on ³⁴⁰K residue and nuclear vicinity localization, and increases its stability, without influencing cell survival.

Key words:

• Tau
• SUMO (Small Ubiquitin‐like Modifier)
• subcellular localization
• signal transduction
• apoptosis
• cell cycle control

Notes

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