Proteomic characterization of LDIP mutant phenotypes in Arabidopsis seedlings

ABSTRACT: Lipid droplets (LDs) are unique, protein-coated organelles found in all eukaryotic organisms that function primarily in the storage of energy-rich neutral lipids, such as triacylglycerols (TAGs). In plants, LDs are found in high abundance in oilseeds, and proteins involved in their formation and activity, such as oleosins, have been well-characterized. Our understanding of LD biogenesis and activity in other cell types, as well as the proteins that regulate these processes, is not as comprehensive. We recently identified and characterized a novel Arabidopsis LD coat protein termed LDIP (LDAP-interacting protein) that regulates LD size and neutral lipid homeostasis in leaf and seed embryonic cells. Here, we show that LDIP plays a distinct role in regulating LD size during biogenesis in leaf cells via interactions with key biogenetic proteins. Localization experiments performed in both plant and insect cells revealed LDIP is necessarily recruited to the LD surface by LDAP3 and binds nascent LDs during early-stage LD formation. Pull-down and Y2H assays indicate LDIP interacts with the biogenetic proteins SEIPINs, while combinatory expression levels of these proteins resulted in aberrant LD size and number in both plant cells and yeast. Evidence is also provided that LDIP plays a key role in modulating phospholipid levels in both leaves and seeds. Taken together, our data allow for the generation of model for LD biogenesis in non-seed cell types.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Seedling

SUBMITTER: Till Ischebeck  

LAB HEAD: D. Till Ischebeck

PROVIDER: PXD012992 | Pride | 2022-02-15

REPOSITORIES: Pride