The water channel gene in human uterus.

The cDNA coding the water channel was isolated from a human uterus cDNA library template by a one-step polymerase chain reaction (PCR). The oligonucleotide primers corresponding to the 5' untranslated nucleotide sequence and complementary to the 3' untranslated nucleotide sequence of the cDNA coding the 28 kDa erythrocyte integral membrane protein (CHIP28) were synthesized and used to initiate the reaction. A 1340 bp cDNA coding the human uterine water channel (hUWC) was cloned and sequenced. The hUWC showed 99.8% and 99% identity with the nucleotide and amino-acid sequences of CHIP28, respectively. The deduced hUWC polypeptide is composed of 269 amino acid residues with a single amino acid variant from CHIP28 protein at position 45, where valine replaces alanine. The hUWC cDNA translated in a prokaryotic protein expression system produced a protein with an estimated Mr of 28 kDa, equivalent to the size of the human red cell CHIP28 protein. The present results suggest that the human uterus contains water channels that may play an important role in regulating water transport and imbibition in the uterus.