Metastatic lymph node 51 (MLN51, also known as CASC3) is a core component of the exon junction complex (EJC), which is loaded onto spliced mRNAs and plays an essential role in determining their fate. Unlike the three other EJC core components [eIF4AIII, Magoh and Y14 (also known as RBM8A)], MLN51 is mainly located in the cytoplasm, where it plays a key role in the assembly of stress granules. In this study, we further investigated the cytoplasmic role of MLN51. We show that MLN51 is a new component of processing bodies (P-bodies). When overexpressed, MLN51 localizes in novel small cytoplasmic foci. These contain RNA, show directed movements and are distinct from stress granules and P-bodies. The appearance of these foci correlates with the process of P-body disassembly. A similar reduction in P-body count is also observed in human HER2-positive (HER2(+)) breast cancer cells overexpressing MLN51. This suggests that P-body disassembly and subsequent mRNA deregulation might correlate with cancer progression.
Overexpression of MLN51 triggers P-body disassembly and formation of a new type of RNA granules
Cougot, N.; Daguenet, E.; Baguet, A.; Cavalier, A.; Thomas, D.; Bellaud, P.; Fautrel, A.; Godey, F.; Bertrand, E.; Tomasetto, C.; Gillet, R.
J Cell Sci
2014-11-01 / vol 127 / pages 4692-701
10.1242/jcs.154500 jcs.154500 [pii]
1477-9137 (Electronic) 0021-9533 (Linking)