8.A.102.1.7
Reticulon-like protein B13, RTNLB13, of 206 aas and 4 TMSs, the smallest of the 21 reticulon-like proteins in A. thaliana (Chow et al. 2018). A curvature-sensing amphipathic (APH) helix in the C-terminus of RTNLB13 is conserved in all endoplasmic reticulum shaping reticulons in Arabidopsis thaliana (Brooks et al. 2021). Reticulons with the closest evolutionary relationship to RTNLB13 contain curvature-sensing APHs in the same location with sequence conservation, but  a more distantly-related branch of reticulons developed a ~ 20-residue linker between the transmembrane domain and APH. This may facilitate functional flexibility as previous studies have linked these isoforms not only to ER remodeling but to other cellular activities (Brooks et al. 2021).