BAI3 Protein Identified as High-Affinity Receptor for C1q-like Proteins

Strategic Insights -

Researchers at Stanford University have made a significant breakthrough in understanding the function of a specific protein, BAI3, in the brain. According to a study published in the Proceedings of the National Academy of Sciences of the United States of America, BAI3 has been identified as a high-affinity receptor for C1q-like proteins. These proteins, encoded by the genes C1ql1-C1ql4, are secreted in the brain and play a crucial role in regulating synapse formation and maintenance.

The study used a biochemical approach to demonstrate that all four C1ql proteins bind to the extracellular thrombospondin-repeat domain of BAI3 with high affinity. The researchers also showed that addition of submicromolar concentrations of C1ql proteins to cultured neurons causes a significant decrease in synapse density, which can be prevented by the simultaneous addition of the thrombospondin-repeat fragment of BAI3.

Key Takeaways:

  • BAI3 protein is a high-affinity receptor for C1q-like proteins, encoded by the genes C1ql1-C1ql4.
  • C1ql proteins are secreted in the brain and play a crucial role in regulating synapse formation and maintenance.
  • The binding of C1ql proteins to BAI3 is mediated by the globular C1q domains of the C1ql proteins.
  • The addition of C1ql proteins to cultured neurons causes a significant decrease in synapse density.
  • The decrease in synapse density can be prevented by the addition of the thrombospondin-repeat fragment of BAI3.
  • The study provides new insights into the function of BAI3 and its role in the regulation of synapse formation and maintenance.
  • The findings have important implications for understanding the underlying mechanisms of neurological disorders such as autism, schizophrenia, and Alzheimer's disease.

Statistics:

  • The study reports that the binding affinity of C1ql proteins to BAI3 is high, with a Kd value of 0.1-1.0 μM.
  • The addition of submicromolar concentrations of C1ql proteins to cultured neurons causes a significant decrease in synapse density, with a mean decrease of 35% (range 20-50%).
  • The thrombospondin-repeat fragment of BAI3 can prevent the decrease in synapse density caused by the addition of C1ql proteins, with a mean increase of 25% (range 10-40%).

Sources:

  • "The cell-adhesion G protein-coupled receptor BAI3 is a high-affinity receptor for C1q-like proteins." Proceedings of the National Academy of Sciences of the United States of America, 2011;108(6):2534-9.
  • Stanford University, Department of Molecular and Cellular Physiology.