PAQR8

PAQR8

PAQR8, also known as Progestin and AdipoQ Receptor family member 8, is a protein encoded by the PAQR8 gene in humans. This protein is part of the PAQR family, which includes receptors that are structurally similar to G protein-coupled receptors (GPCRs) but function through different mechanisms. PAQR8 is primarily known for its role in mediating the effects of certain steroid hormones, particularly progesterone.

Structure

PAQR8 is a membrane protein that spans the cell membrane multiple times, forming a structure that allows it to interact with both extracellular and intracellular molecules. The protein is characterized by its seven transmembrane domains, a hallmark of the PAQR family, which is reminiscent of the structure seen in GPCRs. However, unlike classical GPCRs, PAQR8 does not couple with G proteins to exert its effects.

Function

The primary function of PAQR8 is to act as a receptor for progesterone, a steroid hormone involved in the menstrual cycle, pregnancy, and embryogenesis. PAQR8 mediates non-genomic actions of progesterone, meaning it can initiate cellular responses without directly altering gene expression. This is achieved through the activation of intracellular signaling pathways that can lead to rapid physiological changes.

PAQR8 is involved in various biological processes, including:

• Regulation of reproductive functions
• Modulation of immune responses
• Influence on metabolic pathways

Expression

PAQR8 is expressed in a variety of tissues, with significant expression in the reproductive organs such as the ovaries and uterus. It is also found in the brain, where it may play a role in neurosteroid signaling, and in adipose tissue, where it could influence metabolic processes.

Clinical Significance

Alterations in PAQR8 expression or function have been implicated in several health conditions. For instance, dysregulation of PAQR8 may contribute to reproductive disorders, such as infertility or polycystic ovary syndrome (PCOS). Additionally, its role in metabolism suggests that it could be a factor in metabolic diseases like obesity or type 2 diabetes.

Research is ongoing to better understand the full range of PAQR8's functions and its potential as a therapeutic target. Modulating PAQR8 activity could offer new avenues for treating conditions related to its physiological roles.

Also see

• Progesterone
• Steroid hormone receptors
• G protein-coupled receptors
• Reproductive endocrinology
• Metabolic disorders