Download MendeleyThree-dimensional structure/function analysis of SCP-2-like2 reveals differences among SCP-2 family members.
Dyer, D.H., Wessely, V., Forest, K.T., Lan, Q.(2008) J Lipid Res 49: 644-653
- PubMed: 18084051
- DOI: https://doi.org/10.1194/jlr.M700460-JLR200
- Primary Citation of Related Structures:
2QZT, 3BDQ - PubMed Abstract:
Mosquito sterol carrier protein-2 (AeSCP-2) and sterol carrier protein-2-like2 (AeSCP-2L2) are members of the SCP-2 protein family with similar expression profiles in the mosquito life cycle. In an effort to understand how lipids can be transported by different SCP-2 proteins, the three-dimensional crystal structure of AeSCP-2L2 was solved at 1.7 A resolution. AeSCP-2L2 forms a dimer and binds three fatty acids, one of which resides in a position within the internal cavity at a right angle to the others. This first report of ligand-bound dimerized protein in the SCP-2 protein family indicates that the family has a much more divergent mode of interaction with ligands than previously reported. The potential function of AeSCP-2L2 was investigated via in vivo incorporation of [(3)H]cholesterol and [3H]palmitic acid. Overexpression of AeSCP-2L2 in mosquito cells leads to an increased uptake of free fatty acid, whereas knockdown of AeSCP-2L2 in adult females decreases the accumulation of free fatty acid in the fat body from a blood meal. In contrast, overexpression or knockdown of AeSCP-2L2 has no effect on cholesterol uptake. Our results suggest that the main function of AeSCP-2L2 is as a general intracellular fatty acid carrier, as opposed to having a dedicated role in cholesterol transport.
Organizational Affiliation:
Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
