TY - JOUR
T1 - LAP proteins are localized at the post-synaptic membrane of neuromuscular junctions and appear to modulate synaptic morphology and transmission
AU - Kravic, Bojana
AU - Huraskin, Danyil
AU - Frick, Alexander D.
AU - Jung, Jasmin
AU - Redai, Veronika
AU - Palmisano, Ralf
AU - Marchetto, Sylvie
AU - Borg, Jean Paul
AU - Mei, Lin
AU - Hashemolhosseini, Said
N1 - Publisher Copyright:
© 2016 International Society for Neurochemistry
PY - 2016/11/1
Y1 - 2016/11/1
N2 - Erbin, Lano, Scribble, and Densin-180 belong to LAP (leucine-rich repeats and PDZ domain) adaptor proteins involved in cell signaling pathways. Previously, we identified Erbin, Lano, and Scribble, but not Densin-180, in muscle cells, where they are involved in regulating the aggregation of nicotinic acetylcholine receptors in vitro. Here, we analyzed their cellular localization at the neuromuscular junction (NMJ) in skeletal muscles of mice. Erbin, Lano, and Scribble were significantly accumulated at NMJs and localized in different synaptic cells. Moreover, we used mouse mutants to analyze the role of Erbin at the NMJ. We used two Erbin mutant mouse strains that either completely lack Erbin protein (Erbinnull/null) or express a truncated Erbin mutant where the carboxy-terminal PDZ domain is replaced by β-galactosidase (ErbinΔC/ΔC) thereby abolishing its interaction with ErbB receptor tyrosine kinases. Neither the lack of the PDZ domain of Erbin, nor its complete absence interfered with the general localization of LAP proteins at NMJs, but Lano and Scribble transcript levels were up-regulated in homozygous Erbin-null muscles. Furthermore, grip strength was reduced and neural transmission impaired in homozygous aged Erbin-null but not Erbin-ΔC mice. Erbin-null skeletal muscles did not reveal any conspicuous impairment of the muscle fiber. Localization of other NMJ marker proteins was not affected either. Quantitative 3D morphometry showed that NMJs of Erbin-null muscles were significantly smaller and fragmented in the soleus. We speculate that Erbin, Lano, and Scribble act at the post-synaptic membrane of NMJs in a concerted fashion to regulate nicotinic acetylcholine receptors cluster morphology and neural transmission. (Figure presented.). Cover Image for this issue: doi: 10.1111/jnc.13340.
AB - Erbin, Lano, Scribble, and Densin-180 belong to LAP (leucine-rich repeats and PDZ domain) adaptor proteins involved in cell signaling pathways. Previously, we identified Erbin, Lano, and Scribble, but not Densin-180, in muscle cells, where they are involved in regulating the aggregation of nicotinic acetylcholine receptors in vitro. Here, we analyzed their cellular localization at the neuromuscular junction (NMJ) in skeletal muscles of mice. Erbin, Lano, and Scribble were significantly accumulated at NMJs and localized in different synaptic cells. Moreover, we used mouse mutants to analyze the role of Erbin at the NMJ. We used two Erbin mutant mouse strains that either completely lack Erbin protein (Erbinnull/null) or express a truncated Erbin mutant where the carboxy-terminal PDZ domain is replaced by β-galactosidase (ErbinΔC/ΔC) thereby abolishing its interaction with ErbB receptor tyrosine kinases. Neither the lack of the PDZ domain of Erbin, nor its complete absence interfered with the general localization of LAP proteins at NMJs, but Lano and Scribble transcript levels were up-regulated in homozygous Erbin-null muscles. Furthermore, grip strength was reduced and neural transmission impaired in homozygous aged Erbin-null but not Erbin-ΔC mice. Erbin-null skeletal muscles did not reveal any conspicuous impairment of the muscle fiber. Localization of other NMJ marker proteins was not affected either. Quantitative 3D morphometry showed that NMJs of Erbin-null muscles were significantly smaller and fragmented in the soleus. We speculate that Erbin, Lano, and Scribble act at the post-synaptic membrane of NMJs in a concerted fashion to regulate nicotinic acetylcholine receptors cluster morphology and neural transmission. (Figure presented.). Cover Image for this issue: doi: 10.1111/jnc.13340.
KW - Erbin
KW - Lano
KW - Scribble
KW - neuromuscular junction
KW - nicotinic acetylcholine receptor
UR - http://www.scopus.com/inward/record.url?scp=84979708070&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84979708070&partnerID=8YFLogxK
U2 - 10.1111/jnc.13710
DO - 10.1111/jnc.13710
M3 - Article
C2 - 27321929
AN - SCOPUS:84979708070
SN - 0022-3042
VL - 139
SP - 381
EP - 395
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
IS - 3
ER -