aPKC acts upstream of PAR-1b in both the establishment and maintenance of mammalian epithelial polarity

被引:247
作者
Suzuki, A [1 ]
Hirata, M
Kamimura, K
Maniwa, R
Yamanaka, T
Mizuno, K
Kishikawa, M
Hirose, H
Amano, Y
Izumi, N
Miwa, Y
Ohno, S
机构
[1] Yokohama City Univ, Sch Med, Dept Mol Biol, Yokohama, Kanagawa 2360004, Japan
[2] Univ Tsukuba, Dept Pharmacol, Inst Basic Med Sci, Tsukuba, Ibaraki 3058575, Japan
基金
日本学术振兴会;
关键词
D O I
10.1016/j.cub.2004.08.021
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Background: aPKC and PARA are required for cell polarity in various contexts. In mammalian epithelial cells, aPKC localizes at tight junctions(TJs) and playsan indispensable role in the development of asymmetric intercellular junctions essential for the establishment and maintenance of apicobasal polarity. On the other hand, one of the mammalian PAR-1 kinases, PAR-1b/EMK1/ MARK2, localizes to the lateral membrane in a complimentary manner with aPKC, but little is known about its role in apicobasal polarity of epithelial cells as well as its functional relationship with aPKC. Results: We demonstrate that PAR-1b is essential for the asymmetric development of membrane domains of polarized MDCK cells. Nonetheless, it is not required for the junctional localization of aPKC nor the formation of TJs, suggesting that PAR-1b works downstream of aPKC during epithelial cell polarization. On the other hand, aPKC phosphorylates threonine 595 of PAR-1b and enhances its binding with 14-3-3/PAR-5. In polarized MDCK cells, T595 phosphorylation and 14-3-3 binding are observed only in the soluble form of PAR-1b, and okadaic acid treatment induces T595-dependent dissociation of PAR-1b from the lateral membrane. Furthermore, T595A mutation induces not only PAR-1b leakage into the apical membrane, but also abnormal development of membrane domains. These results suggest that in polarized epithelial cells, aPKC phosphorylates PAR-1b at TJs, and in cooperation with 14-3-3, promotes the dissociation of PAR-1b from the lateral membrane to regulate PAR-1b activity for the membrane domain development. Conclusions: These results suggest that mammalian aPKC functions upstream of PAR-1b in both the establishment and maintenance of epithelial cell polarity.
引用
收藏
页码:1425 / 1435
页数:11
相关论文
共 42 条
[1]   Drosophila PAR-1 and 14-3-3 inhibit Bazooka/PAR-3 to establish complementary cortical domains in polarized cells [J].
Benton, R ;
St Johnston, D .
CELL, 2003, 115 (06) :691-704
[2]   Drosophila 14-3-3/PAR-5 is an essential mediator of PAR-1 function in axis formation [J].
Benton, R ;
Palacios, IM ;
St Johnston, D .
DEVELOPMENTAL CELL, 2002, 3 (05) :659-671
[3]   The Par complex directs asymmetric cell division by phosphorylating the cytoskeletal protein Lgl [J].
Betschinger, J ;
Mechtler, K ;
Knoblich, JA .
NATURE, 2003, 422 (6929) :326-330
[4]   Mammalian homologues of C-elegans PAR-1 are asymmetrically localized in epithelial cells and may influence their polarity [J].
Bohm, H ;
Brinkmann, V ;
Drab, M ;
Henske, A ;
Kurzchalia, TV .
CURRENT BIOLOGY, 1997, 7 (08) :603-606
[5]  
Boyd L, 1996, DEVELOPMENT, V122, P3075
[6]   A system for stable expression of short interfering RNAs in mammalian cells [J].
Brummelkamp, TR ;
Bernards, R ;
Agami, R .
SCIENCE, 2002, 296 (5567) :550-553
[7]   Mammalian PAR-1 determines epithelial lumen polarity by organizing the microtubule cytoskeleton [J].
Cohen, D ;
Brennwald, PJ ;
Rodriguez-Boulan, E ;
Müsch, A .
JOURNAL OF CELL BIOLOGY, 2004, 164 (05) :717-727
[8]   Drosophila par-1 is required for oocyte differentiation and microtubule organization [J].
Cox, DN ;
Lu, BW ;
Sun, TQ ;
Williams, LT ;
Jan, YN .
CURRENT BIOLOGY, 2001, 11 (02) :75-87
[9]   The role of PAR-1 in regulating the polarised microtubule cytoskeleton in the Drosophila follicular epithelium [J].
Doerflinger, H ;
Benton, R ;
Shulman, JM ;
St Johnston, D .
DEVELOPMENT, 2003, 130 (17) :3965-3975
[10]   MAPs, MARKs and microtubule dynamics [J].
Drewes, G ;
Ebneth, A ;
Mandelkow, EM .
TRENDS IN BIOCHEMICAL SCIENCES, 1998, 23 (08) :307-311