title: Erbin regulates NRG1 signaling and myelination.
abstract: Neuregulin 1 (NRG1) plays a critical role in myelination. However, little is known about regulatory mechanisms of NRG1 signaling. We show here that Erbin, a protein that contains leucine-rich repeats (LRR) and a PSD95-Dlg-Zol (PDZ) domain and that interacts specifically with ErbB2, is necessary for NRG1 signaling and myelination of peripheral nervous system (PNS). In Erbin null mice, myelinated axons were hypomyelinated with reduced expression of P0, a marker of mature myelinating Schwann cells (SCs), whereas unmyelinated axons were aberrantly ensheathed in Remak bundles, with increased numbers of axons in the bundles and in pockets. The morphological deficits were associated with decreased nerve conduction velocity and increased sensory threshold to mechanistic stimulation. These phenotypes were duplicated in erbin(DeltaC/DeltaC) mice, in which Erbin lost the PDZ domain to interact with ErbB2. Moreover, ErbB2 was reduced at protein levels in both Erbin mutant sciatic nerves, and ErbB2 became unstable and NRG1 signaling compromised when Erbin expression was suppressed. These observations indicate a critical role of Erbin in myelination and identify a regulatory mechanism of NRG1 signaling. Our results suggest that Erbin, via the PDZ domain, binds to and stabilizes ErbB2, which is necessary for NRG1 signaling that has been implicated in tumorigenesis, heart development, and neural function.
authors.affiliation: Department of Neurology, Institute of Molecular Medicine and Genetics, Medical College of Georgia, Augusta, GA 30912, USA.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Tao
authors.forename: Penggao
authors.initials: P
authors.lastname: Dai
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Sylvie
authors.initials: S
authors.lastname: Marchetto
authors.forename: Wen-Cheng
authors.initials: WC
authors.lastname: Xiong
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Borg
authors.forename: Lin
authors.initials: L
authors.lastname: Mei
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D009186:Myelin Sheath / Q000378:metabolism*; D020890:Neuregulin-1 / Q000378:metabolism*; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D012584:Sciatic Nerve / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D020890:Neuregulin-1; D018719:Erb-b2 Receptor Tyrosine Kinases; C498804:Erbb2ip protein, mouse