title: Relationship between annexin A7 and integrin β4 in autophagy.
abstract: We recently found that both annexin A7 and integrin β4 were involved in autophagy of vascular endothelial cells. But, their relation is not clear. In this study, we addressed this question by using a small molecule ABO that promoted autophagy by targeting annexin A7. The results showed that knockdown of integrin β4 partly inhibited ABO-induced autophagy in vascular endothelial cells. Furthermore, in HEK293 cells that express integrin β4 too low to detect by western blot, ABO could not induce autophagy. If integrin β4 was overexpressed in HEK293 cells, ABO could evoke autophagy. On the other hand, knockdown of annexin A7 also blocked ABO-induced autophagy although the level of integrin β4 was elevated. Moreover, by co-immunoprecipitation, we identified the interaction of integrin β4 and annexin A7, and found that ABO could modulate the interaction, at the same time, the phosphorylation of Y-1494 in integrin β4 cytoplasmic domain was inhibited significantly in vitro and in vivo. Hence, by identifying the interaction between integrin β4 and annexin A7, we demonstrated that both annexin A7 and integrin β4 were essential for small molecule ABO-induced autophagy and targeting annexin A7 by ABO could modulate integrin β4 phosphorylation, while Y-1494 phosphorylation of integrin β4 may negatively regulate autophagy.
authors.affiliation: Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Science, Shandong University, Jinan 250100, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Li
authors.forename: Shuya
authors.initials: S
authors.lastname: Huang
authors.forename: Shengqing
authors.initials: S
authors.lastname: Wang
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Qi
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shangli
authors.initials: S
authors.lastname: Zhang
authors.forename: Baoxiang
authors.initials: B
authors.lastname: Zhao
authors.forename: Junying
authors.initials: J
authors.lastname: Miao
mesh_terms: D000818:Animals; D017310:Annexin A7 / Q000378:metabolism*; D001057:Apolipoproteins E / Q000172:deficiency / Q000378:metabolism; D001343:Autophagy / Q000187:drug effects; D048588:Benzoxazines / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism; D055785:Gene Knockdown Techniques; D020868:Gene Silencing / Q000187:drug effects; D057809:HEK293 Cells; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D039663:Integrin beta4 / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010766:Phosphorylation / Q000187:drug effects; D010769:Phosphothreonine / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects
chemical_list: C541593:6-amino-2,3-dihydro-3-hydroxymethyl-1,4-benzoxazine; D017310:Annexin A7; D001057:Apolipoproteins E; D048588:Benzoxazines; D039663:Integrin beta4; D010769:Phosphothreonine
keywords: 6-amino-2, 3-dihydro-3-hydroxymethyl-1, 4-benzoxazine; ABO; ANXA7; Annexin A7; ApoE(−/−) mice; Autophagy; ECPC; HD; HUVEC; Human umbilical vein endothelial cell; Integrin β4; LC3; Phosphorylation; VEC; apolipoprotein E-deficient mice; ethyl1-(3-(4-chlorophenoxy)-2-hydroxypropyl)-3-(4-chlorophenyl)-1H-pyrazole-5-carboxylate; hemidesmosome; microtubule-associated protein 1 light chain 3; oxLDL; oxidized low-density lipoprotein; vascular endothelial cell