Although the mechanisms of regulation of calcium-related genes in the uterus are not fully understood, it is likely that the regulation of calcium ion flux is complex, and involves a diverse set of proteins. For example, implantation in CaBP-9k knockout is normal, while CaBP-9k/28k double knockout mice experience failed
NHS-LC-Biotin implantation [5]. These results indicate that more than two calcium regulatory proteins participate in embryo implantation. There is also evidence that NCKX3 is involved in specific functions during female reproduction involving other calcium-processing
proteins [4], [7] and [8]. NCKX3 is expressed at lower levels in the uterus, aorta, and intestine, which are rich in smooth muscle [3], [11], [17] and [18]. However, the role of NCKX3 in the uterus is not yet firmly established. In the present study, we demonstrated that NCKX3 localizes to the endothelial layer and glands of the mouse uterus, which suggests that NCKX3 plays a role in uterine smooth muscle contraction and fetal implantation.
