Lipid Droplet Is an Ancient and Inheritable Organelle in Bacteria

Abstract

Lipid droplet (LD) is a monolayer phospholipid membrane-bound organelle found in all eukaryotes and several prokaryotes which plays key roles in cellular lipid homeostasis and human health. The origin and evolution of the organelle remains unknown. Here, we report that through screening over 660 bacteria using biophysical and biochemical methods, plus LD isolation and proteomic tool, LDs were identified in most of these microbes, affiliated with five main bacterial phyla. Moreover, LDs were also identified in E. coli overexpressing lipid synthesis enzymes, indicating that bacteria without detectable LDs possessed the ability of LD biogenesis. The similarity of isolated LDs from representative strains and evolutionary analysis of LD major protein PspA demonstrate that LDs were conserved in bacteria. Furthermore, time-lapse imaging revealed that LDs were inheritable accompanying with bacterial growth and division. Finally, a common ancestor of LD-containing bacteria was predicted to originate 3.19 billion years ago by a phylogenetic analysis. Our findings suggest that LD is a widespread and inheritable organelle from an ancient common ancestor.

Mechanisms of Lipid Droplet Accumulation in Steatotic Liver Diseases

“…Lipid droplet (LD) organelles are highly conserved organelles that are at least 3.1 billion years old. 1 LDs are the intracellular hubs of lipid metabolism in all cells and are increasingly acknowledged as the disease-defining organelles of several hepatic steatotic diseases. Debated as a bona fide organelle as recently as 2006, 2 LDs have since emerged as the organelles that harbor most of the genetic risk for two common hepatic steatotic diseases, metabolic dysfunction-associated steatotic liver disease (MASLD, formerly called nonalcoholic fatty liver disease) and alcohol-associated liver disease (ALD).…”

Lipid droplets and the transcriptome of Mycobacterium tuberculosis from direct sputa: a literature review

“…These names includes lipid droplet (LD), lipid body (LB), intracellular lipid inclusions (ILI), oil body (OB), adiposome, spherosome and oleosome. Lipid droplets are pervasive and dynamic subcellular organelles of diverse morphological and functional diversity [18][19][20][21] across evolutionary tree of life. Lipid droplets comprised of a hydrophobic core of neutral lipids (triacylglycerol, TAG and cholesterol ester, CE) surrounded by a phospholipid monolayer of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylinositol (PI) and lyso-phospholipids; decorated with different types of proteins such as Perilipins (PLIN) [22,23] (Fig.…”