De novo lipid synthesis and polarized prenylation drives cell invasion through basement membrane

SummaryInvasive cells form large, specialized protrusions to break through basement membrane (BM) matrix barriers. Park et al., reveal a crucial requirement for de novo lipid synthesis and a dynamic polarizing prenylation system to rapidly construct invasive protrusions that breach BMs. To breach basement membrane (BM), cells in development and cancer use large, transient, specialized lipid-rich membrane protrusions. Using live imaging, endogenous protein tagging, and cell-specific RNAi during C. elegans anchor cell (AC) invasion, we demonstrate that the lipogenic SREBP transcription factor SBP-1 drives expression of the fatty acid synthesis enzymes POD-2 and FASN-1 prior to invasion. We show that phospholipid producing LPIN-1 and sphingomyelin synthase SMS-1, which use fatty acids as substrates, produce lysosome stores that build the ACs invasive protrusion, and that SMS-1 also promotes protrusion localization of the lipid raft partitioning ZMP-1 matrix metalloproteinase. Finally, we discover that the endoplasmic reticulum (ER)-associated HMG-CoA reductase HMGR-1, which generates isoprenoids for prenylation, enriches at the AC invasive front, and that the final ER prenylation enzyme, ICMT-1, localizes to ER exit sites that dynamically polarize to deliver prenylated GTPases for protrusion formation. Together, these results reveal a collaboration between lipogenesis and a polarized lipid prenylation system that drives invasive protrusion formation.