Hepatocyte polarity establishment and apical lumen formation are organized by Par3, Cdc42, and aPKC in conjunction with Lgl
| Autor: | Sachiko Kamakura, Akira Kohda, Hideki Sumimoto, Junya Hayase, Vlad Tocan, Motoyuki Kohjima, Shouichi Ohga |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
PBR
polybasic region Male Cell Cycle Proteins CDC42 Biochemistry Mice Cell polarity Cdc42 cdc42 GTP-Binding Protein SIM structured illumination microscopy Cells Cultured Protein Kinase C Mice Inbred ICR Tight junction Chemistry Multidrug resistance-associated protein 2 NA numerical aperture Cell Polarity MDCK Madin–Darby canine kidney Hep G2 Cells Lgl Par3 ECM extracellular matrix Cell biology Isoenzymes TJ tight junction medicine.anatomical_structure Hepatocyte atypical protein kinase C PM plasma membrane CCR C-terminal conserved region Research Article MEM minimum essential medium cDNA complementary DNA FBS fetal bovine serum MRP2 multidrug resistance protein 2 BC bile canaliculus hepatocyte medicine Animals Humans aPKC atypical protein kinase C Molecular Biology Adaptor Proteins Signal Transducing Matrigel HEK 293 cells Cell Biology HEK293T human embryonic kidney 293T Apical membrane DPP4 dipeptidyl peptidase IV Cytoskeletal Proteins Hepatocytes BSA bovine serum albumin |
| Zdroj: | The Journal of Biological Chemistry |
| ISSN: | 0021-9258 |
| DOI: | 10.1016/j.jbc.2021.101354 |
| Popis: | Hepatocytes differ from columnar epithelial cells by their multipolar organization, which follows the initial formation of central lumen-sharing clusters of polarized cells as observed during liver development and regeneration. The molecular mechanism for hepatocyte polarity establishment, however, has been comparatively less studied than those for other epithelial cell types. Here we show that the tight junction protein Par3 organizes hepatocyte polarization via cooperating with the small GTPase Cdc42 to target atypical protein kinase C (aPKC) to a cortical site near the center of cell-cell contacts. In 3D Matrigel culture of human hepatocytic HepG2 cells, which mimics a process of liver development and regeneration, depletion of Par3, Cdc42, or aPKC results in an impaired establishment of apico-basolateral polarity and a loss of subsequent apical lumen formation. The aPKC activity is also required for bile canalicular (apical) elongation in mouse primary hepatocytes. The lateral membrane-associated proteins Lgl1 and Lgl2, major substrates of aPKC, seem to be dispensable for hepatocyte polarity establishment, because Lgl-depleted HepG2 cells are able to form a single apical lumen in 3D culture. On the other hand, Lgl depletion leads to lateral invasion of aPKC, and overexpression of Lgl1 or Lgl2 prevents apical lumen formation, indicating that they maintain proper lateral integrity. Thus, hepatocyte polarity establishment and apical lumen formation are organized by Par3, Cdc42, and aPKC; Par3 cooperates with Cdc42 to recruit aPKC, which plays a crucial role in apical membrane development and regulation of the lateral maintainer Lgl. |
| Databáze: | OpenAIRE |
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