PMID:11294845

Citation	Brandes, C, Kahr, L, Stockinger, W, Hiesberger, T, Schneider, WJ and Nimpf, J (2001) Alternative splicing in the ligand binding domain of mouse ApoE receptor-2 produces receptor variants binding reelin but not alpha 2-macroglobulin. J. Biol. Chem. 276:22160-9
Abstract	LR7/8B and ApoER2 are recently discovered members of the low density lipoprotein (LDL) receptor family. Although structurally different, these two proteins are derived from homologous genes in chicken and man by alternative splicing and contain 7 or 8 LDL receptor ligand-binding repeats. Here we present the cDNA for ApoER2 cloned from mouse brain and describe splice variants in the ligand binding domain of this protein, which are distinct from those present in man and chicken. The cloned cDNA is coding for a receptor with only five LDL receptor ligand-binding repeats, i.e. comprising repeats 1-3, 7, and 8. Reverse transcriptase-polymerase chain reaction analysis of mRNA from murine brain revealed the existence of two additional transcripts. One is lacking repeat 8, and in the other repeat 8 is substituted for by a 13-amino acid insertion with a consensus site for furin cleavage arising from an additional small exon present in the murine gene. None of the transcripts in the mouse, however, contain repeats 4-6. In murine placenta only the form containing repeats 1-3 and 7 and the furin cleavage site is detectable. Analysis of the corresponding region of the murine gene showed the existence of 6 exons coding for a total of 8 ligand binding repeats, with one exon encoding repeats 4-6. Exon trapping experiments demonstrated that this exon is constitutively spliced out in all murine transcripts. Thus, the murine ApoER2 gene codes for receptor variants harboring either 4 or 5 binding repeats only. Recombinant expression of the 5-repeat and 4-repeat variants showed that repeats 1-3, 7, and 8 are sufficient for binding of beta-very low density lipoprotein and reelin, but not for recognition of alpha(2)-macroglobulin, which binds to the avian homologue of ApoER2 harboring 8 ligand binding repeats.
Links	PubMed Online version:10.1074/jbc.M102662200
Keywords	Alternative Splicing; Amino Acid Sequence; Animals; Base Sequence; Binding Sites; Cell Adhesion Molecules, Neuronal/metabolism; Cloning, Molecular; DNA, Complementary; Exons; Extracellular Matrix Proteins/metabolism; Introns; LDL-Receptor Related Proteins; Ligands; Mice; Molecular Sequence Data; Nerve Tissue Proteins; Receptors, Lipoprotein/chemistry; Receptors, Lipoprotein/genetics; Receptors, Lipoprotein/metabolism; Reverse Transcriptase Polymerase Chain Reaction; Serine Endopeptidases; alpha-Macroglobulins/metabolism
edit table

Annotations

Gene product	Qualifier	GO ID	GO term name	Evidence Code	with/from	Aspect	Notes	Status
edit table

References

See Help:References for how to manage references in GONUTS.