Structural decoding of netrin-4 reveals a regulatory function towards mature basement membranes
Raphael Reuten1,2, Trushar R Patel3,4, Matthew McDougall5
1Institute for Dental Research and Oral Musculoskeletal Biology, Medical Faculty, University of Cologne, Joseph-Stelzmann-Strasse 52, Cologne 50931, Germany.
Nature Communications
|December 1, 2016
Summary
Netrin-4, unlike netrin-1, does not bind to known receptors. Instead, netrin-4 disrupts laminin networks and basement membranes, revealing its novel extracellular matrix role in development and disease.
Area of Science:
- Molecular Biology
- Developmental Biology
- Neuroscience
Background:
- Netrins are laminin-related molecules involved in nervous system and vascular development.
- Netrin-1 uses DCC and UNC5 receptors for guidance.
- Netrin-4 was hypothesized to function similarly to netrin-1, interacting with its receptors.
Purpose of the Study:
- To determine the high-resolution structure of netrin-4.
- To investigate netrin-4's binding interactions with known netrin-1 receptors.
- To elucidate the mechanism by which netrin-4 influences extracellular matrix and developmental processes.
Main Methods:
- High-resolution structural analysis of netrin-4.
- Receptor-binding assays for netrin-1 receptors (DCC, UNC5s).
- Analysis of netrin-4's interaction with laminin and basement membranes.
Main Results:
- Netrin-4 possesses unique structural features compared to netrin-1.
- Netrin-4 does not directly bind to DCC or UNC5 receptors.
- Netrin-4 binds with high affinity to the laminin γ1 chain, disrupting laminin networks and basement membranes.
Conclusions:
- Netrin-4 functions distinctly from netrin-1, not relying on shared receptor pathways.
- Netrin-4 acts as a non-enzymatic extracellular matrix modulator, actively disrupting basement membranes.
- This novel mechanism likely underlies netrin-4's roles in axon growth and angiogenesis.
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