EXPLORING IN VIVO FUNCTIONS OF Yarrowia lipolytica STEROL CARRIER PROTEIN 2 (YLSCP-2)

ALEJO ROMÁN GIANOTTI; RAÚL GABRIEL FERREYRA; FEDERICO PÉREZ DE BERTI; CINTHIA YASMIN SCOTT; NOELIA INÉS BURGARDT; MARIO ROBERTO ERMÁCORA

Sierra de la Ventana

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

Sterol Carrier Protein 2 (SCP2) is a nonspecific lipid transfer protein that has been implicated in the transfer, uptake, and metabolism of cholesterol, branched-chain fatty acids, acyl-CoA conjugates, and other lipids. SCP2 are present as domains of multidomain proteins or as single domain polypeptides in all forms of life. SCP2 structure and function has been studied mostly in mammals and next in insects. In these organisms, it has been generally found that the main function of this protein is in the peroxysomal degradation of lipids. We have previously shown that Yarrowia lipolytica SCP2 (YLSCP2) is a 128-amino-acid basic protein inducible by fatty acids, that it is located in the yeast peroxisomes and able to bind a variety of lipids and transfer them to membranes by a collision-mediated mechanism. YLSCP2 structure was recently resolved in our lab. X-ray diffraction of the protein shows the lipid binding site as a large system of interconnected tunnels and surface pockets partially occupied by palmitate. However, very little is known about the function of this protein in plants, yeast and prokaryotes. Intriguingly, Saccharomyces cerevisiae and S. pombe are the only fungi known to lack SCP2 or any similar domain. For this reason, we express the YLSCP-2 gene in S. cerevisiae in order to evaluate the physiological function of this protein. We found that cells expressing the protein are more sensitive to oxidative stress compared to cells lacking the protein. So, we hypothesized that YLSCP2 may be involved in the oxidative stress response, kidnapping peroxidized lipids generated by oxidative stress and disseminating those to different structures in the cells.