The role of post-Golgi transport pathways and sorting motifs in the plasmodesmal targeting of the movement protein (MP) of Ourmia melon virus (OuMV)

Natali Ozber; Paolo Margaria; Charles T. Anderson; Massimo Turina; Cristina Rosa

Conversely, substitutions of leucine and isoleucine with a pair of glycine residues impair the transport of the OuMV MP to PD. In mammals and yeast, LL motifs are recognized by APs 1-3 with a combination of two subunits: AP1 γ-σ1, AP2 α-σ2, and AP3 δ-σ3 hemicomplexes (Janvier et al., 2003; Doray et al., 2007) . The acidic amino acid is not as crucial as dileucine residues for binding to AP2 (Kelly et al., 2008) . The binding specificity of plant AP complexes has yet to be elucidated. Only one study has explored direct binding of a canonical LL motif to subunits of AP complexes. The dileucine motif of Arabidopsis tonoplast-localized ion transporter VTI1, EKQTLL, interacts with AP1 γ1/2 and σ1/2 subunits, but not with AP3 δ and σ (Wang et al., 2014) , raising the possibility that these subunits could be interacting partners of OuMV MP instead of AP2M. Although we cannot exclude the possibility that the LL motif may be important for . CC-BY-NC-ND 4.0 International license is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. It . https://doi.org/10.1101/724716 doi: bioRxiv preprint binding of other proteins, our study addresses the function of this motif in the intracellular targeting of OuMV MP.