Phytolongins are a new family of non-SNAREs longins in plant cells. Four proteins have been identified in Arabidopsis (Phyl 1.1, 1.2, 2.1 and 2.2) and their subcellular localization and trafficking has been determined in this work published by our team (Valerie Wattelet-Boyer, Guillaume Bouyssou, Claireline Marais, Yohann Boutté and Patrick Moreau ) in Journal of Experimental Botany with the strong collaboration of Carine de Marcos Lousa (University of Leeds-Becket) and Francesco Filippini (University of Padova).

In this study, we found that the four phytolongins are distributed along the secretory pathway, Phyl2.1 and Phyl2.2 were strictly located at the ER network, Phyl1.2 at the Golgi bodies and Phyl1.1 was mainly associated to the plasma membrane and partially to post-Golgi compartments. Our results show that Phyl1.1 export from the ER depends on the GTPase Sar1, the Sar1 guanine nucleotide exchange factor Sec12, and the SNAREs Sec22 and Memb11. In addition, we have identified the Y48F49 motif as being critical for the escape of Phyl1.1 from the ER. Our results provide the first characterization of the sub-cellular localization of this new class of longins called phytolongins and discuss their potential roles in membrane structure and trafficking.