Membrane progesterone receptor

[1] The mPRs mediate important physiological functions in male and female reproductive tracts, liver, neuroendocrine tissues, and the immune system as well as in breast and ovarian cancer.

[9] A recent study[10] has investigated the role of mPRβ in regulating in vitro maturation (IVM) of pig cumulus-oocyte complexes (COCs).

Scientists found that mPRγ is expressed in female mouse reproductive tissues such as ovary and fallopian tube, and also in the lung and liver of both sexes.

That suggests a common role for mPRγ in the regulation of ciliary activity in the fallopian tube and the gamete transport in mammals.

The presence of mPRγ in lung and liver of mice indicates that the receptor mediates the actions of progesterone outside the reproductive tract as well.

[15] Family members include:[16] The general functions of these subtypes of mPR are: being steroid membrane receptors and binding progesterone.

[1] Extensive evidence has been obtained by different research groups that wild-type mPRs in a wide range of vertebrate cells as well as recombinant proteins expressed in prokaryotic and eukaryotic systems display high-affinity, specific, displaceable and limited capacity progesterone binding characteristic of steroid membrane receptors.

[1][21] MPRs are also considered potential intermediaries in progesterone modulation of GnRH secretion under certain conditions, but direct evidence is lacking.

The presence of functional mPRα, mPRβ, and mPRγ subtypes were detected in both cell lines as well as in breast tumor tissues.

Notably, the expression of mPRγ was significantly higher in endometrioid and clear cell carcinomas, which are closely related tumors.

[26] Recent studies suggest that some progesterone actions in astrocytoma cells (the most common and malignant human brain tumors) may be mediated also by mPRs.