PhD Thesis Topic
Influence of S-acylation on SNARE proteins role
SNARE proteins (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) belong to a superfamily of small membrane proteins and mediate membrane fusion events in all of the trafficking steps of both secretory and endocytic pathways.
Despite considerable sequence divergence among SNARE proteins, their mechanism of action is evolutionarily conserved from yeast to humans. Many SNAREs are posttranslationaly S-acylated.
S-acylation involves the enzymatic addition of long-chain lipids, most typically palmitate, onto cysteine residues via a reversible thioester bond. For peripheral membrane proteins, the foremost function of S-acylation is to mediate stable membrane attachment. In the case of transmembrane proteins, like many SNAREs, the effect of the S-acylation is less clear. Multiple members of the SNARE family have been reported to be S-acylated on cysteine residues located close to, or within, its transmembrane domain, although in most cases the functional role is very poorly understood.
We have designed a system that allows us to purify S-acylated SNARE proteins from S. cerevisiae. Using these proteins, I plan to study the effect of S-acylation on the role of SNARE proteins through liposomes fusion assays. Additionally I’ll study the effect of S-acylation on the biophysical behaviour of SNAREs. i.e the differential targeting of SNAREs to membrane microdomains of either different lipids composition or curvature.