| First Author | Kumari SS | Year | 2019 |
| Journal | Biochem Biophys Res Commun | Volume | 511 |
| Issue | 3 | Pages | 626-630 |
| PubMed ID | 30826060 | Mgi Jnum | J:290305 |
| Mgi Id | MGI:6442083 | Doi | 10.1016/j.bbrc.2019.02.098 |
| Citation | Kumari SS, et al. (2019) A predominant form of C-terminally end-cleaved AQP0 functions as an open water channel and an adhesion protein in AQP0(DeltaC/DeltaC) mouse lens. Biochem Biophys Res Commun 511(3):626-630 |
| abstractText | 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 (AQP0(DeltaC/DeltaC)) that does not express intact AQP0. A genetically engineered KI mouse model, AQP0(DeltaC/DeltaC), 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(+/DeltaC) lenses were transparent; AQP0(-/-) and AQP0(DeltaC/DeltaC) 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(+/DeltaC) and AQP0(DeltaC/DeltaC); 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<0.001) in Pf and CTCA compared to those of WT. AQP0(+/DeltaC) and AQP0(DeltaC/DeltaC) FCMVs exhibited no statistically significant alteration (P>0.05) in Pf compared to those of WT. However, CTCA of AQP0(+/DeltaC) AQP0(DeltaC/DeltaC) FCMVs was significantly higher (P<0.001) than that of WT FCMVs. Our experiments clearly show that C-terminally end-cleaved AQP0 can function both as a water channel and a CTCA molecule in the lens fiber cell membranes. Also, end-truncation plays an important role in increasing the CTCA between fiber cells. |
