Elucidating the role of the DUF 828 gene family of Arabidopsis thaliana in auxin transport

The FORKED1 (FKD1) gene encodes a protein with a Domain of Unknown Function (DUF828) and a Pleckstrin Like Domain. The Arabidopsis thaliana genome contains 9 genes with a DUF828 domain whose function has never been characterized. FKD1 localizes to various BFA insensitive post-­Golgi compartments and also forms a component of ARF mediated vesicle trafficking, supported by the colocalization of FKD1 with SFC/VAN3 (ARF-­ AP) and ARF1 proteins. FKD1 colocalization with PIN1 suggests its role in PIN1 protein trafficking. Several DUF828 family members show colocalization with FKD1 suggesting their possible redundancy in vesicle trafficking pathway. I have identified four genes in the DUF828 family that act redundantly to establish vein meeting in root elongation and root gravitropism in Arabidopsis. PIN1 localization in the developing veins of triple mutants is highly defective indicating the role of the DUF828 family in establishing PIN1 polarity.