The endoplasmic reticulum (ER) is a dynamic organelle with multiple functions. It is comprised of distinct morphological domains. Regulation of this morphology and its dynamics are mediated by several highly conserved families of proteins, namely the reticulon (RTN) proteins responsible for generating high curvature membranes, Lunapark (LNP) proteins mediating cisternae formation, and ROOT HAIR DEFECTIVE 3 (RHD3/Atlastin/Sey1p) which is required for 3-way junction formation. The differential expression of these proteins induces changes in ER morphology, and morphological dysregulation has been associated with disruptions in overall cellular function. Within the Arabidopsis genome, there are 21 RTN genes, across 6 protein clades. Clade 1-4 RTNs have been demonstrated to induce tubule formation, and upon over-expression produce a hyperconstriction phenotype on ER tubules. This function is mediated via the reticulon homology domain (RHD), which contains 4 transmembrane domains (TMDs). The 'W' shaped topology allows the RTNs to induce hydrophobic wedging and subsequent curvature of the ER membrane, and which is stabilised via oligomerisation of RTNs. Clade 5 RTNs, were previously characterised and found to localise distinctly different to clade 1-4 RTNs and are involved in regulation of sterol contents in roots due to the presence of a 3β-hydroxysteroid dehydrogenase domain (3βHSD). In this body of work, the three members of clade 6 RTNs are characterised for the first time, revealing that RTN17, RTN18 and RTN21 localise to distinct punctate structures across the ER network. Analysis of RTN17.1 interacting partners indicates it could act as a hub protein utilising intrinsically disordered termini to interact with RHD3, and associates with the cytoskeletal network to promote homotypic fusion within the ER. Clade 6 RTNs are functionally distinct from clade 1-5 RTNs, and quantitative analysis of over-expression phenotypes reveal a distinct morphological profile linked to their suggested role in 3-way junction formation.