Description
Aquaporin 10 (AQP10) was identified in human small intestine. This gene encoded a 264-amino-acid protein with high sequence identity with AQP3 (53%), -9(52%), and -7(43%). These AQPs constitute one subfamily of AQP family that is differentiated from the other subfamily of AQP (AQP0, 1, 2, 4, 5, 6, and 8) by sequence homology. In situ hybridization analysis demonstrated highest expression of AQP10 in absorptive epithelial cells at the tips of villi in the jejunum. SDS-PAGE analysis showed expression of a 28-kD protein, similar to its predicted size as well as to that of the other AQPs. Functional analysis indicated that cells expressing AQP10 are permeable to relatively low amounts of water, but, unlike AQP3, -7, and -9, are not permeable to urea or glycerol