Positively Charged Amino Acid Residues in the Extracellular Loops A and C of Lens Aquaporin 0 Interact with the Negative Charges in the Plasma Membrane to Facilitate Cell-to-cell Adhesion

Overview

Journal Exp Eye Res

Specialty Ophthalmology

Date 2019 Jun 1

PMID 31150637

Citations 6

Authors

Sindhu Kumari

Gozde Taginik

Sangeeth Varadaraj

Kulandaiappan Varadaraj

Affiliations

Soon will be listed here.

Abstract

This investigation was undertaken to find out whether the positive charges in the Extracellular Loops A (ELA) and C (ELC) of Aquaporin 0 (AQP0) are involved in lens fiber cell-to-cell adhesion (CTCA), and the possible mechanism of CTCA. AQP0 ELA or ELC was substituted with the corresponding AQP1 loop via Polymerase Chain Reaction. Positively charged arginine (R) and histidine (H) of mouse AQP0 ELA and ELC were substituted individually with glutamine (Q) to create R33Q, H40Q, R113Q and H122Q by mutagenesis. cRNA expression, immunostaining, Förster Resonance Energy Transfer (FRET) studies and protein analyses showed localization of all mutants except AQP0-AQP1ELC chimera (AQP0 ELC substituted with AQP1 ELC) at the plasma membrane. Osmotic Swelling Assay revealed comparable water permeability (P) among AQP0-AQP1ELA, R33Q, R113Q, and WT. CTCA assay demonstrated a significant reduction in adhesion in all mutants compared to the WT (14-73%) suggesting the importance of the conserved positively charged residues of ELA and ELC for adhesion. Studies involving AQP0-transfected L-cells, and lipid vesicles indicated that CTCA was due to the electrostatic interaction between the positively charged amino acids of AQP0 extracellular loops and the negative charges of the plasma membrane. Schematic models are provided to illustrate the mechanism.

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References

Varadaraj K, Kumari S, Mathias R . Transgenic expression of AQP1 in the fiber cells of AQP0 knockout mouse: effects on lens transparency. Exp Eye Res. 2010; 91(3):393-404. PMC: 2926274. DOI: 10.1016/j.exer.2010.06.013. View

Varadaraj K, Kumari S . Molecular mechanism of Aquaporin 0-induced fiber cell to fiber cell adhesion in the eye lens. Biochem Biophys Res Commun. 2018; 506(1):284-289. PMC: 6223623. DOI: 10.1016/j.bbrc.2018.10.066. View

Scheuring S, Buzhynskyy N, Jaroslawski S, Goncalves R, Hite R, Walz T . Structural models of the supramolecular organization of AQP0 and connexons in junctional microdomains. J Struct Biol. 2007; 160(3):385-94. DOI: 10.1016/j.jsb.2007.07.009. View

Michea L, de la Fuente M, Lagos N . Lens major intrinsic protein (MIP) promotes adhesion when reconstituted into large unilamellar liposomes. Biochemistry. 1994; 33(24):7663-9. DOI: 10.1021/bi00190a021. View

Harries W, Akhavan D, Miercke L, Khademi S, Stroud R . The channel architecture of aquaporin 0 at a 2.2-A resolution. Proc Natl Acad Sci U S A. 2004; 101(39):14045-50. PMC: 521118. DOI: 10.1073/pnas.0405274101. View

Xu L, Overbeek P, Reneker L . Systematic analysis of E-, N- and P-cadherin expression in mouse eye development. Exp Eye Res. 2002; 74(6):753-60. DOI: 10.1006/exer.2002.1175. View

Kumari S, Varadaraj M, Yerramilli V, Menon A, Varadaraj K . Spatial expression of aquaporin 5 in mammalian cornea and lens, and regulation of its localization by phosphokinase A. Mol Vis. 2012; 18:957-67. PMC: 3340213. View

Kumari S, Varadaraj K . Intact and N- or C-terminal end truncated AQP0 function as open water channels and cell-to-cell adhesion proteins: end truncation could be a prelude for adjusting the refractive index of the lens to prevent spherical aberration. Biochim Biophys Acta. 2014; 1840(9):2862-77. PMC: 4127142. DOI: 10.1016/j.bbagen.2014.05.002. View

Hass M, Mulder F . Contemporary NMR Studies of Protein Electrostatics. Annu Rev Biophys. 2015; 44:53-75. DOI: 10.1146/annurev-biophys-083012-130351. View

10.

Veneziale R, Grunwald G, Menko A . N-cadherin function is required for differentiation-dependent cytoskeletal reorganization in lens cells in vitro. Exp Cell Res. 2000; 256(1):237-47. DOI: 10.1006/excr.2000.4819. View

11.

Chauvigne F, Fjelldal P, Cerda J, Finn R . Auto-Adhesion Potential of Extraocular Aqp0 during Teleost Development. PLoS One. 2016; 11(5):e0154592. PMC: 4859563. DOI: 10.1371/journal.pone.0154592. View

12.

Lo W, Biswas S, Brako L, Shiels A, Gu S, Jiang J . Aquaporin-0 targets interlocking domains to control the integrity and transparency of the eye lens. Invest Ophthalmol Vis Sci. 2014; 55(3):1202-12. PMC: 3941616. DOI: 10.1167/iovs.13-13379. View

13.

Varadaraj K, Kumari S, Patil R, Wax M, Mathias R . Functional characterization of a human aquaporin 0 mutation that leads to a congenital dominant lens cataract. Exp Eye Res. 2008; 87(1):9-21. PMC: 2504491. DOI: 10.1016/j.exer.2008.04.001. View

14.

Okamura T, Miyoshi I, Takahashi K, Mototani Y, Ishigaki S, Kon Y . Bilateral congenital cataracts result from a gain-of-function mutation in the gene for aquaporin-0 in mice. Genomics. 2003; 81(4):361-8. DOI: 10.1016/s0888-7543(03)00029-6. View

15.

Shiels A, Bassnett S, Varadaraj K, Mathias R, Kuszak J, Donoviel D . Optical dysfunction of the crystalline lens in aquaporin-0-deficient mice. Physiol Genomics. 2002; 7(2):179-86. DOI: 10.1152/physiolgenomics.00078.2001. View

16.

Zampighi G, Eskandari S, Hall J, Zampighi L, Kreman M . Micro-domains of AQP0 in lens equatorial fibers. Exp Eye Res. 2002; 75(5):505-19. DOI: 10.1006/exer.2002.2041. View

17.

Jensen M, Dror R, Xu H, Borhani D, Arkin I, Eastwood M . Dynamic control of slow water transport by aquaporin 0: implications for hydration and junction stability in the eye lens. Proc Natl Acad Sci U S A. 2008; 105(38):14430-5. PMC: 2533686. DOI: 10.1073/pnas.0802401105. View

18.

Kumari S, Gao J, Mathias R, Sun X, Eswaramoorthy A, Browne N . Aquaporin 0 Modulates Lens Gap Junctions in the Presence of Lens-Specific Beaded Filament Proteins. Invest Ophthalmol Vis Sci. 2017; 58(14):6006-6019. PMC: 5710632. DOI: 10.1167/iovs.17-22153. View

19.

Varadaraj K, Kumari S, Mathias R . Functional expression of aquaporins in embryonic, postnatal, and adult mouse lenses. Dev Dyn. 2007; 236(5):1319-28. PMC: 2534140. DOI: 10.1002/dvdy.21125. View

20.

Kumari S, Gandhi J, Mustehsan M, Eren S, Varadaraj K . Functional characterization of an AQP0 missense mutation, R33C, that causes dominant congenital lens cataract, reveals impaired cell-to-cell adhesion. Exp Eye Res. 2013; 116:371-85. PMC: 3864651. DOI: 10.1016/j.exer.2013.09.019. View