The liver receptor homolog-1 (LRH-1) also known as totipotency pioneer factor NR5A2 (nuclear receptor subfamily 5, group A, member 2) is a protein that in humans is encoded by the NR5A2 gene. [5] [6] LRH-1 is a member of the nuclear receptor family of intracellular transcription factors.
LRH-1 plays a critical role in the regulation of development, cholesterol transport, bile acid homeostasis and steroidogenesis. [7] [8] [9] [10]
LRH-1 is important for maintaining pluripotence of stem cells during embryonic development. [11] [10]
Nr5a2 was recently identified at a totipotent pioneer factor. [10] The orphan nuclear receptor Nr5a2 has been shown to be important in fertility, ovarian function, [12] and zygotic genome activation (ZGA). [10] Heterozygosity for Nr5a2 is associated with reduced ovarian function, specifically in the synthesis of progesterone. This impaired progesterone production was associated with infertility in female mice, as well as increased incidence of pregnancy loss. [12] The loss of embryos around implantation associated with Nr5a2+/- mice indicated a possible interaction with genome-wide gene expression in early embryo development. Upon further investigation, Nr5a2 was found to regulate ZGA in mice embryos similar to that of Zelda in Drosophila. Nr5a2 is maternally contributed and regulates transcription activity in the early embryo by binding to distal cis-regulatory sequences and promoting chromatin accessibility. The change in chromatin conformation allows for the activation of transcription of about 72% of genes involved in ZGA. [10]
Liver receptor homolog-1 has been shown to interact with the small heterodimer partner. [13] [14]
Estrogen receptor alpha (ERα), also known as NR3A1, is one of two main types of estrogen receptor, a nuclear receptor that is activated by the sex hormone estrogen. In humans, ERα is encoded by the gene ESR1.
In the field of molecular biology, the pregnane X receptor (PXR), also known as the steroid and xenobiotic sensing nuclear receptor (SXR) or nuclear receptor subfamily 1, group I, member 2 (NR1I2) is a protein that in humans is encoded by the NR1I2 gene.
The constitutive androstane receptor (CAR) also known as nuclear receptor subfamily 1, group I, member 3 is a protein that in humans is encoded by the NR1I3 gene. CAR is a member of the nuclear receptor superfamily and along with pregnane X receptor (PXR) functions as a sensor of endobiotic and xenobiotic substances. In response, expression of proteins responsible for the metabolism and excretion of these substances is upregulated. Hence, CAR and PXR play a major role in the detoxification of foreign substances such as drugs.
The nuclear receptor 4A1 also known as Nur77, TR3, and NGFI-B is a protein that in humans is encoded by the NR4A1 gene.
The steroidogenic factor 1 (SF-1) protein is a transcription factor involved in sex determination by controlling the activity of genes related to the reproductive glands or gonads and adrenal glands. This protein is encoded by the NR5A1 gene, a member of the nuclear receptor subfamily, located on the long arm of chromosome 9 at position 33.3. It was originally identified as a regulator of genes encoding cytochrome P450 steroid hydroxylases, however, further roles in endocrine function have since been discovered.
The small heterodimer partner (SHP) also known as NR0B2 is a protein that in humans is encoded by the NR0B2 gene. SHP is a member of the nuclear receptor family of intracellular transcription factors. SHP is unusual for a nuclear receptor in that it lacks a DNA binding domain. Therefore, it is technically neither a transcription factor nor nuclear receptor but nevertheless it is still classified as such due to relatively high sequence homology with other nuclear receptor family members.
Peroxisome proliferator-activated receptor gamma, also known as the glitazone reverse insulin resistance receptor, or NR1C3 is a type II nuclear receptor functioning as a transcription factor that in humans is encoded by the PPARG gene.
Rev-Erb alpha (Rev-Erbɑ), also known as nuclear receptor subfamily 1 group D member 1 (NR1D1), is one of two Rev-Erb proteins in the nuclear receptor (NR) family of intracellular transcription factors. In humans, REV-ERBɑ is encoded by the NR1D1 gene, which is highly conserved across animal species.
RAR-related orphan receptor alpha (RORα), also known as NR1F1 is a nuclear receptor that in humans is encoded by the RORA gene. RORα participates in the transcriptional regulation of some genes involved in circadian rhythm. In mice, RORα is essential for development of cerebellum through direct regulation of genes expressed in Purkinje cells. It also plays an essential role in the development of type 2 innate lymphoid cells (ILC2) and mutant animals are ILC2 deficient. In addition, although present in normal numbers, the ILC3 and Th17 cells from RORα deficient mice are defective for cytokine production.
Hepatocyte nuclear factor 4 alpha (HNF4A) also known as NR2A1 is a nuclear receptor that in humans is encoded by the HNF4A gene.
Liver X receptor alpha (LXR-alpha) is a nuclear receptor protein that in humans is encoded by the NR1H3 gene.
Nuclear receptor-interacting protein 1 (NRIP1) also known as receptor-interacting protein 140 (RIP140) is a protein that in humans is encoded by the NRIP1 gene.
Estrogen-related receptor gamma (ERR-gamma), also known as NR3B3, is a nuclear receptor that in humans is encoded by the ESRRG gene. It behaves as a constitutive activator of transcription.
COUP-TF1 also known as NR2F1 is a protein that in humans is encoded by the NR2F1 gene. This protein is a member of nuclear hormone receptor family of steroid hormone receptors.
COUP-TFII, also known as NR2F2 is a protein that in humans is encoded by the NR2F2 gene. The COUP acronym stands for chicken ovalbumin upstream promoter.
The testicular receptor 2 (TR2) also known as NR2C1 is protein that in humans is encoded by the NR2C1 gene. TR2 is a member of the nuclear receptor family of transcription factors.
Testicular receptor 4 also known as NR2C2 is a protein that in humans is encoded by the NR2C2 gene.
Liver X receptor beta (LXR-β) is a member of the nuclear receptor family of transcription factors. LXR-β is encoded by the NR1H2 gene.
DnaJ homolog subfamily B member 1 is a protein that in humans is encoded by the DNAJB1 gene.
Progesterone receptor membrane component 1 is a protein which co-purifies with progesterone binding proteins in the liver and ovary. In humans, the PGRMC1 protein is encoded by the PGRMC1 gene.