A predominant form of C-terminally end-cleaved AQPO functions as an open water channel and an adhesion protein in AQP0ΔC/ΔC mouse lens
A predominant form of C-terminally end-cleaved AQPO functions as an open water channel and an adhesion protein in AQP0ΔC/ΔC mouse lens
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DOI：
10.1016/j.bbrc.2019.02.098
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发表时间：
2019-04-09
影响因子：
3.1
通讯作者：
Varadaraj, Kulandaiappan
中科院分区：
文献类型：
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作者：
Kumari, S. Sindhu;Varadaraj, Kulandaiappan
本研究的目的是发现C末端切割的水蛋白0（AQP 0），主要存在于WT的透镜成熟纤维细胞中，是否在不表达完整AQP 0的敲入（KI）小鼠模型（AQP 0（Δ C/Δ C））中作为水通道和细胞间粘附（CTCA）蛋白发挥作用。开发了仅表达末端切割的AQP 0的基因工程KI小鼠模型AQP 0（Delta C/Delta C）。该模型表达AQP 0的1-246个氨基酸，而不是全长1-263个氨基酸。通过暗场成像定性分析出生后第10天（P10）的透镜透明度。WT、AQP 0（+/-）和AQP 0（+/Δ C）晶状体是透明的; AQP 0（-/-）和AQP 0（Δ C/Δ C）小鼠晶状体显示透明度丧失。从野生型（WT）、AQP 0杂合型（AQP 0（+/-））、AQP 0敲除型（AQP 0（-/-））、AQP 0（+/Δ C）和AQP 0（Δ C/Δ C）制备透镜纤维细胞膜囊泡（FCMVs）;使用渗透收缩法测量水渗透性（p（f））。使用粘附缺陷型L细胞和从上述基因型制备的FCMV进行CTCA测定。AQP 0（+/-）和AQP 0（-/-）的FCMVs在P-f和CTCA中显示与WT相比的统计学显著降低（P < 0.001）。AQP 0（Δ C/Δ C）和AQP 0（Δ C/Δ C）FCMVs在P-f组与WT组相比无显著性差异（P > 0.05）。而AQP 0（+/Δ C）、AQP 0（Δ C/Δ C）FCMVs的CTCA显著高于WT FCMVs（P < 0.001）。我们的实验清楚地表明，C-末端切割AQP 0可以作为水通道和CTCA分子在透镜纤维细胞膜。此外，末端截短在增加纤维细胞之间的CTCA中起重要作用。(C)2019爱思唯尔公司All rights reserved.
The purP0se of this investigation was to find out whether C-terminally end-cleaved aquaP0rin 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(Delta C/Delta C)) that does not express intact AQP0. A genetically engineered KI mouse model, AQP0(Delta C/Delta C), 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 P0stnatal day 10 (P10) was analyzed qualitatively by dark field imaging. WT, AQP0(+/-) and AQP0(+/Delta C) lenses were transparent; AQP0(-/-) and AQP0(Delta C/Delta C) 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(+/Delta C) and AQP0(Delta C/Delta C); water permeability (p(f)) 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 P-f and CTCA compared to those of WT. AQP0(Delta C/Delta C) and AQP0(Delta C/Delta C) FCMVs exhibited no statistically significant alteration (P > 0.05) in P-f compared to those of WT. However, CTCA of AQP0(+/Delta C) AQP0(Delta C/Delta C) 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. (C) 2019 Elsevier Inc. All rights reserved.