A new m6A reader complex

Abstract

N⁶-Methyladenosine (m⁶A) is the most widespread modification of mRNA and is required to control mRNA stability and translation efficiency. In plants, its effect is mediated by m⁶A reader proteins such as EVOLUTIONARILY CONSERVED C-TERMINAL REGION (ECT) proteins. Marlene Reichel from the University of Copenhagen, and colleagues, find that the m⁶A binding and reader function of ECT2 in Arabidopsis requires proteins from the ACETYLATION LOWERS BINDING AFFINITY (ALBA) family, which suggests that these factors form an m⁶A reader complex.

Arabidopsis encodes eleven ECTs; of these, ECT2 and ECT3 have the most important role in post-embryonic development, and ECT4 has a more minor contribution. The ect2 ect3 ect4 (ect2/3/4) triple mutants display delayed organogenesis and aberrant morphology, including misshaped leaves, petals and siliques as well as increased trichome branching. These ECTs bind to m⁶A modifications in the 3′ untranslated region of mRNAs and recruit poly(A) binding proteins to enhance mRNA stability. However, the exact mode of mRNA binding of ECTs and whether other factors are involved was unclear.