
Occludin is a target of Src kinase and promotes lipid secretion by binding to BTN1a1 and XOR
Author(s) -
Yunzhe Lu,
Tao Zhou,
Chongshen Xu,
Rui Wang,
Feng Ding,
Jiyong Li,
Xu Wang,
Yu Kong,
Guohong Hu,
Xiangyin Kong,
Pengfei Lu
Publication year - 2022
Publication title -
plos biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.127
H-Index - 271
eISSN - 1545-7885
pISSN - 1544-9173
DOI - 10.1371/journal.pbio.3001518
Subject(s) - biology , secretion , occludin , microbiology and biotechnology , biogenesis , kinase , lipid metabolism , proto oncogene tyrosine protein kinase src , phosphorylation , biochemistry , tight junction , gene
Lipid droplets (LDs) have increasingly been recognized as an essential organelle for eukaryotes. Although the biochemistry of lipid synthesis and degradation is well characterized, the regulation of LD dynamics, including its formation, maintenance, and secretion, is poorly understood. Here, we report that mice lacking Occludin ( Ocln ) show defective lipid metabolism. We show that LDs were larger than normal along its biogenesis and secretion pathway in Ocln null mammary cells. This defect in LD size control did not result from abnormal lipid synthesis or degradation; rather, it was because of secretion failure during the lactation stage. We found that OCLN was located on the LD membrane and was bound to essential regulators of lipid secretion, including BTN1a1 and XOR, in a C-terminus–dependent manner. Finally, OCLN was a phosphorylation target of Src kinase, whose loss causes lactation failure. Together, we demonstrate that Ocln is a downstream target of Src kinase and promotes LD secretion by binding to BTN1a1 and XOR.