Usuki Seigo, Tamura Noriko, Tamura Tomohiro, Mukai Katsuyuki, Igarashi Yasuyuki
Lipid Biofunction Section, Frontier Research Center for Advanced Material and Life Science, Faculty of Advanced Life Science, Hokkaido University.
National Institute of Advanced Industrial Science and Technology (AIST).
J Oleo Sci. 2018 Jan 1;67(1):87-94. doi: 10.5650/jos.ess17142. Epub 2017 Dec 14.
Konjac ceramide (kCer) can be prepared by a chemoenzymatic method as previously published (Usuki, S.; Tamura, N.; Sakai, S.; Tamura, T.; Mukai, K.; Igarashi, Y. Biochem. Biophys. Rep. 5, 160-167 (2016)). Thus prepared kCer showed an activation effect on Sema3A signaling pathway to induce phosphorylation of CRMP2 and microtubule depolymerizaion, resulting in opposing NGF-induced neurite outgrowth. In the present study, we have shown that kCer is a potential Sema3A-like ligand that has a competitive effect on Sema3A binding to a cell surface receptor Nrp1, but animal-type ceramides have no effect on Sema3A binding to Nrp1. In addition, kCer showed a direct molecular interaction with Nrp1, but animal-type ceramides, C16Cer, C18Cer, and C24Cer show no specific bindings to Nrp1. Further, kCer showed an additive effect to activate the Sema3A signaling pathway together with low-dose Sema3A but a reversed effect to inhibit this pathway when combined with high-dose Sema3A.
魔芋神经酰胺（kCer）可以通过先前发表的化学酶法制备（臼杵，S.；田村，N.；酒井，S.；田村，T.；向井，K.；五十岚，Y.《生物化学与生物物理报告》5，160 - 167（2016年））。如此制备的kCer对Sema3A信号通路显示出激活作用，可诱导CRMP2磷酸化和微管解聚，从而对抗神经生长因子（NGF）诱导的神经突生长。在本研究中，我们已经表明kCer是一种潜在的类Sema3A配体，对Sema3A与细胞表面受体Nrp1的结合具有竞争作用，但动物型神经酰胺对Sema3A与Nrp1的结合没有影响。此外，kCer与Nrp1表现出直接的分子相互作用，但动物型神经酰胺，C16Cer、C18Cer和C24Cer与Nrp1没有特异性结合。进一步地，kCer与低剂量Sema3A一起对激活Sema3A信号通路具有累加效应，但与高剂量Sema3A联合时对该通路具有相反的抑制作用。
