Estrone sulfotransferase

Estrone sulfotransferase (EST), also known as estrogen sulfotransferase, is an enzyme that in humans is encoded by the SULT1E1 gene. This enzyme is part of the sulfotransferase family, a group of enzymes that catalyze the sulfation of various compounds, making them more soluble and easier to excrete from the body. Estrone sulfotransferase specifically catalyzes the sulfation of estrogens, which is a crucial step in the metabolism and excretion of these hormones.

Function

Estrone sulfotransferase plays a vital role in the regulation of estrogen levels within the body. By sulfating estrogens, such as estrone and estradiol, it effectively reduces their biological activity, as sulfated estrogens cannot bind to estrogen receptors. This process is essential for maintaining hormonal balance and is involved in various physiological processes, including reproductive functions and the menstrual cycle.

Clinical Significance

The activity of estrone sulfotransferase can have significant implications for various medical conditions. Abnormal levels of this enzyme can lead to disorders related to estrogen imbalance, such as estrogen dominance, which can contribute to conditions like endometriosis, fibroids, and certain types of breast cancer. Furthermore, the enzyme's role in estrogen metabolism makes it a target for certain drugs aimed at treating estrogen-related disorders.

Genetic Regulation

The SULT1E1 gene, located on chromosome 4q13.1, encodes the estrone sulfotransferase enzyme. Genetic variations in SULT1E1 can affect the enzyme's activity and, consequently, an individual's ability to metabolize estrogens. Studies have suggested that polymorphisms in the SULT1E1 gene may influence susceptibility to diseases such as breast cancer, though more research is needed to fully understand these associations.

Pharmacology

In the context of pharmacology, inhibitors of estrone sulfotransferase are being explored for their potential therapeutic applications in treating estrogen-related disorders. By inhibiting this enzyme, it may be possible to increase the levels of active estrogens in targeted tissues, offering a novel approach to therapy for conditions like menopausal symptoms, osteoporosis, and certain cancers.

See Also

• Sulfotransferase
• Estrogen metabolism
• Hormonal regulation