The central fragment of Reelin, generated by proteolytic processing in vivo, is critical to its function during cortical plate development.
Reelin is a large extracellular protein that controls cortical development. It binds to lipoprotein receptors very-low-density lipoprotein receptor and apolipoprotein-E receptor type 2, thereby inducing phosphorylation of the adapter Dab1. In vivo, Reelin is cleaved into three fragments, but their respective function is unknown. Here we show the following: (1) the central fragment is necessary and sufficient for receptor binding in vitro and for Dab1 phosphorylation in neuronal cultures; (2) Reelin does not bind the protocadherin cadherin-related neuronal receptor (CNR1) as reported previously; (3) Reelin and its central fragment are equally able to rescue the reeler phenotype in a slice culture assay; and (4) anti-receptor antibodies can induce Dab1 phosphorylation but do not correct the reeler phenotype in slices. These observations show that the function of Reelin is critically dependent on the central fragment generated by processing but primarily independent of interactions with CNR1 and on the N-terminal region. They also indicate that events acting in parallel to Dab1 phosphorylation might be required for full activity.
Jossin
Yves
Y
Developmental Genetics Unit, University of Louvain Medical School, B1200 Brussels, Belgium.
Ignatova
Nina
N
Hiesberger
Thomas
T
Herz
Joachim
J
Lambert de Rouvroit
Catherine
C
Goffinet
André M
AM
D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001665:Binding Sites; D015820:Cadherins / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D002460:Cell Line; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D016326:Extracellular Matrix Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D026502:LDL-Receptor Related Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008818:Mice, Neurologic Mutants; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism; D010641:Phenotype; D000091363:Protocadherins; D011956:Receptors, Cell Surface; D011973:Receptors, LDL / Q000276:immunology / Q000378:metabolism; D018110:Receptors, Lipoprotein / Q000276:immunology / Q000378:metabolism; D000091042:Reelin Protein; D012697:Serine Endopeptidases
D000906:Antibodies; D015820:Cadherins; D015816:Cell Adhesion Molecules, Neuronal; C103773:Dab1 protein, mouse; D016326:Extracellular Matrix Proteins; D026502:LDL-Receptor Related Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C484820:PCDHA4 protein, human; C113143:Pcdha4 protein, mouse; D000091363:Protocadherins; D011956:Receptors, Cell Surface; D011973:Receptors, LDL; D018110:Receptors, Lipoprotein; D000091042:Reelin Protein; C036053:VLDL receptor; C098773:low density lipoprotein receptor-related protein 8; C000717127:RELN protein, human; C000717128:Reln protein, mouse; D012697:Serine Endopeptidases