Proteomic analysis of Metarhizium robertsii Lipid Droplets

Metarhizium robertsii is one of the model fungus species widely used studying insect-fungus interactions. Our previous studies have shown the accumulation of lipid droplets (LDs) play an essential role in generation of cellular turgor pressure to assist fungal penetration of insect cuticles, and autophagy-related proteins are connected with LD biogenesis and cellular accumulation in M. robertsii. However, full proteomes of LDs are unclear in terms of the species of proteins involved in lipid biosynthesis and degradation. We performed experiments by growing the fungi in different nutrient conditions, isolated the LDs and extracted the LD proteins from the cultures after being grown in a nutrient-rich medium (i.e. Sabouraud dextrose broth, SDB), a minimum medium without nitrogen source (MM-N) and MM-N supplemented with oleate. The protein samples were then subject to LC-MS/MS proteome profilings for identifying and postulating the proteins/pathways involved in lipid metabolisms.