Elucidating the Functional Role of TDRD3 in Stress Granules

Abstract

Tudor domain-containing protein 3, TDRD3, was first identified in a proteomic survey of the spliceosome machinery. Although its function remains elusive, elevated TDRD3 gene expression is associated with poor prognosis of estrogen receptor-negative breast cancer. The Tudor domain of TDRD3 is highly similar to the Tudor domain of the survival of motor neuron (SMN) and accordingly, it has been shown to bind dimethylated arginine residues. Our lab has previously demonstrated the association of TDRD3 with the translation machinery and most importantly, its localization to stress granules (SG) upon various cellular stresses. In this study, it was revealed that TDRD3 knockdown facilitates and accelerates SG assembly and consequently accelerates SG disassembly. Moreover, we showed that wildtype TDRD3 rescued this defect while a mutation in the Tudor domain of TDRD3, E691K, was not able to do so. Taken together, these findings allude to a prominent role for TDRD3, via its Tudor domain, in the proper formation of SGs.