A G protein-coupled receptor with low density lipoprotein-binding motifs suggests a role for lipoproteins in G-linked signal transduction.
We have isolated and analyzed a cDNA from the central nervous system of the mollusc Lymnaea stagnalis encoding a putative receptor, which might be a natural hybrid between two different classes of receptor proteins. Preceded by a signal peptide, two types of repeated sequences are present in the N-terminal part of the protein. The first repeat displays a high sequence similarity to the extracellular binding domains of the low density lipoprotein receptor, which binds and internalizes cholesterol-containing apolipoproteins. The second repeat and the C-terminal part of the Lymnaea receptor are very similar to regions of a specific class of guanine nucleotide-binding protein-coupled receptors, the mammalian glycoprotein hormone receptors. The mRNA encoding the receptor is predominantly expressed in a small number of neurons within the central nervous system and to a lesser extent in the heart.
Tensen
C P
CP
Department of Zoology, Graduate School of Neurosciences Amsterdam, Vrije Universiteit, Faculty of Biology, The Netherlands.
Van Kesteren
E R
ER
Planta
R J
RJ
Cox
K J
KJ
Burke
J F
JF
van Heerikhuizen
H
H
Vreugdenhil
E
E
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008195:Lymnaea; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011973:Receptors, LDL / Q000378:metabolism*; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
D008077:Lipoproteins, LDL; D011956:Receptors, Cell Surface; D011973:Receptors, LDL; D004247:DNA; D019204:GTP-Binding Proteins