Tandem repeat subunit of reelin and related proteins.
Reelin is an extracellular glycoprotein involved in neuronal development, specifically in the brain cortex. It contains 8 tandemly repeated units, each of which is composed of two highly similar subrepeats and a central EGF domain. This model characterizes the subrepeats, which directly contact each other in a compact arrangement. Consecutive reelin repeat units are packed together to form an overall rod-like molecular structure. Reelin repeats 5 and 6 are reported to interact with neuronal receptors, the apolipoprotein E receptor 2 (ApoER2) and the very-low-density lipoprotein receptor (VLDLR), triggering a signaling cascade upon binding and subsequent tyrosine phosphorylation of the cytoplasmic disabled-1 (Dab1). Genetic deficiency of reelin, or ApoER2 and VLDLR, or Dab1, all exhibit the same phenotypes, including ataxia, cortical layer inversion and abnormal positioning patterns.
Jiyao W et al.(2023). "The conserved domain database in 2023.",