TY - JOUR
T1 - Spontaneous assembly and active disassembly balance adherens junction homeostasis
AU - Hong, Soonjin
AU - Troyanovsky, Regina B.
AU - Troyanovsky, Sergey M.
PY - 2010/2/23
Y1 - 2010/2/23
N2 - The homeostasis of adherens junctionswasstudied using E-cadherin and its two mutants tagged by the photoconvertible protein Dendra2 in epithelial A-431 cells and in CHO cells lacking endogenous cadherin. The first mutant contained point mutations of two elements, Lys738 and the dileucine motif that suppressed cadherin endocytosis. The second mutant contained, in addition, an extensive truncation that uncoupled the mutant from β-catenin and p120. Surprisingly, the intact cadherin and its truncated mutant were recruited into the junctions with identical kinetics. The full-size cadherin was actively removed from the junctions by a process that was unaffected by the inactivation of its endocytic elements. The cadherin's apparent half-residence time in the junction was about 2 min. Cadherin clusters made of the truncated mutant exhibited much slower but ATP-independent junctional turnover. Taken together, our experiments showed that adherens junction homeostasis consists of three distinctive steps: cadherin spontaneous recruitment, its lateral catenin-dependent association, and its active release from the resulting clusters. The latter process, whose mechanism is not clear, may play an important role in various kinds of normal and abnormal morphogenesis.
AB - The homeostasis of adherens junctionswasstudied using E-cadherin and its two mutants tagged by the photoconvertible protein Dendra2 in epithelial A-431 cells and in CHO cells lacking endogenous cadherin. The first mutant contained point mutations of two elements, Lys738 and the dileucine motif that suppressed cadherin endocytosis. The second mutant contained, in addition, an extensive truncation that uncoupled the mutant from β-catenin and p120. Surprisingly, the intact cadherin and its truncated mutant were recruited into the junctions with identical kinetics. The full-size cadherin was actively removed from the junctions by a process that was unaffected by the inactivation of its endocytic elements. The cadherin's apparent half-residence time in the junction was about 2 min. Cadherin clusters made of the truncated mutant exhibited much slower but ATP-independent junctional turnover. Taken together, our experiments showed that adherens junction homeostasis consists of three distinctive steps: cadherin spontaneous recruitment, its lateral catenin-dependent association, and its active release from the resulting clusters. The latter process, whose mechanism is not clear, may play an important role in various kinds of normal and abnormal morphogenesis.
KW - Cadherin
KW - Catenins
KW - Cell-cell adhesion
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U2 - 10.1073/pnas.0911027107
DO - 10.1073/pnas.0911027107
M3 - Article
C2 - 20133579
AN - SCOPUS:77649263931
SN - 0027-8424
VL - 107
SP - 3528
EP - 3533
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 8
ER -