Arabidopsis thaliana plastoglobule-associated fibrillin 1a interacts with fibrillin 1b in vivo

Plant fibrillins are a well-conserved protein family found in the plastids of all photosynthetic organisms, where they perform a wide range of functions. A number of these proteins have been suggested to be involved in the maintenance of thylakoids and the formation of plastoglobules, preventing their coalescence and favoring their clustering via an as-yet unidentified cross-linking mechanism. In this work we show that two members of this group, namely fibrillin 1a and 1b, interact with each other via a head-to-tail mechanism, thus raising the possibility that they form homo- or hetero-oligomers and providing a mechanism to understand the function of these proteins.