A predominant form of C-terminally end-cleaved AQP0 functions as an open water channel and an adhesion protein in AQP0ΔC/ΔC mouse lens

Autor: Kulandaiappan Varadaraj, S. Sindhu Kumari
Rok vydání: 2019
Předmět:
Zdroj: Biochemical and Biophysical Research Communications. 511:626-630
ISSN: 0006-291X
DOI: 10.1016/j.bbrc.2019.02.098
Popis: The purpose of this investigation was to find out whether C-terminally end-cleaved aquaporin 0 (AQP0), that is present predominantly in the lens mature fiber cells of the WT, functions as a water channel and a cell-to-cell adhesion (CTCA) protein in a knockin (KI) mouse model (AQP0ΔC/ΔC) that does not express intact AQP0. A genetically engineered KI mouse model, AQP0ΔC/ΔC, expressing only end-cleaved AQP0 was developed. This model expresses 1–246 amino acids of AQP0, instead of the full length 1–263 amino acids. Lens transparency of postnatal day 10 (P10) was analyzed qualitatively by dark field imaging. WT, AQP0+/− and AQP0+/ΔC lenses were transparent; AQP0−/− and AQP0ΔC/ΔC mouse lenses displayed loss of transparency. Lens fiber cell membrane vesicles (FCMVs) were prepared from wild type (WT), AQP0 heterozygous (AQP0+/−), AQP0 knockout (AQP0−/−), AQP0+/ΔC and AQP0ΔC/ΔC; water permeability (Pf) was measured using the osmotic shrinking method. CTCA assay was performed using adhesion-deficient L-cells and FCMVs prepared from the abovementioned genotypes. FCMVs of AQP0+/− and AQP0−/− showed a statistically significant reduction (P 0.05) in Pf compared to those of WT. However, CTCA of AQP0+/ΔC AQP0ΔC/ΔC FCMVs was significantly higher (P
Databáze: OpenAIRE
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