cDNA cloning and expression of oxysterol-binding protein, an oligomer with a potential leucine zipper

PA Dawson, ND Ridgway, CA Slaughter… - Journal of Biological …, 1989 - Elsevier
PA Dawson, ND Ridgway, CA Slaughter, MS Brown, JL Goldstein
Journal of Biological Chemistry, 1989Elsevier
Feedback repression of the genes encoding the low density lipoprotein receptor and several
enzymes of the cholesterol biosynthetic pathway is mediated by 25-hydroxycholesterol and
other oxysterols. In this study, we have cloned a rabbit cDNA encoding an oxysterol-binding
protein that may play a role in this regulation. The predicted amino acid sequence revealed
a protein of 809 amino acids with two distinctive features: 1) a glycine-and alanine-rich
region (63% of 80 residues) at the NH2 terminus, and 2) a 35-residue leucine zipper motif …
Feedback repression of the genes encoding the low density lipoprotein receptor and several enzymes of the cholesterol biosynthetic pathway is mediated by 25-hydroxycholesterol and other oxysterols. In this study, we have cloned a rabbit cDNA encoding an oxysterol-binding protein that may play a role in this regulation. The predicted amino acid sequence revealed a protein of 809 amino acids with two distinctive features: 1) a glycine- and alanine-rich region (63% of 80 residues) at the NH2 terminus, and 2) a 35-residue leucine zipper motif that may mediate the previously observed oligomerization of the protein. When transfected into simian COS cells, the rabbit cDNA produced a protein that exhibited the same affinity and specificity for sterols as the previously purified hamster liver protein. Immunoblotting analysis showed that the rabbit cDNA encodes both the 96- and 101-kilodalton forms of the oxysterol-binding protein that were previously observed. The availability of an expressible cDNA for the oxysterol-binding protein should help elucidate its role in sterol metabolism.
Elsevier