RT Journal Article
SR Electronic
T1 Phosphorylation hotspot in the C-terminal domain of occludin regulates the dynamics of epithelial junctional complexes
JF Journal of Cell Science
JO J. Cell Sci.
FD The Company of Biologists Ltd
SP jcs206789
DO 10.1242/jcs.206789
VO 131
IS 7
A1 Manda, Bhargavi
A1 Mir, Hina
A1 Gangwar, Ruchika
A1 Meena, Avtar S.
A1 Amin, Shrunali
A1 Shukla, Pradeep K.
A1 Dalal, Kesha
A1 Suzuki, Takuya
A1 Rao, RadhaKrishna
YR 2018
UL http://jcs.biologists.org/content/131/7/jcs206789.abstract
AB The apical junctional complex (AJC), which includes tight junctions (TJs) and adherens junctions (AJs), determines the epithelial polarity, cell-cell adhesion and permeability barrier. An intriguing characteristic of a TJ is the dynamic nature of its multiprotein complex. Occludin is the most mobile TJ protein, but its significance in TJ dynamics is poorly understood. On the basis of phosphorylation sites, we distinguished a sequence in the C-terminal domain of occludin as a regulatory motif (ORM). Deletion of ORM and expression of a deletion mutant of occludin in renal and intestinal epithelia reduced the mobility of occludin at the TJs. ORM deletion attenuated Ca2+ depletion, osmotic stress and hydrogen peroxide-induced disruption of TJs, AJs and the cytoskeleton. The double point mutations T403A/T404A, but not T403D/T404D, in occludin mimicked the effects of ORM deletion on occludin mobility and AJC disruption by Ca2+ depletion. Both Y398A/Y402A and Y398D/Y402D double point mutations partially blocked AJC disruption. Expression of a deletion mutant of occludin attenuated collective cell migration in the renal and intestinal epithelia. Overall, this study reveals the role of ORM and its phosphorylation in occludin mobility, AJC dynamics and epithelial cell migration.