all-trans Retinol (Vitamin A), Retinoic acid receptor ligand

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

The Estrogen Receptor known as ER is a critical protein involved in the regulation of gene expression by binding to estrogen hormones. It plays a role in various physiological processes such as reproductive and cardiovascular functions. There are two main subtypes: ERα and ERβ. ERα is approximately 66 kDa and ERβ is around 54 kDa. The receptor is predominantly expressed in tissues such as breast ovary bone heart and brain. It is also identified in non-reproductive systems like the cardiovascular system. Another protein of interest RBP4 (Retinol Binding Protein 4) is responsible for transporting vitamin A (all-trans retinol) to tissues. RBP4 is mainly expressed in the liver and adipose tissue and aids in maintaining normal vision.

Biological function summary

Both the estrogen receptor and retinol binding protein 4 are involved in significant physiological processes. The estrogen receptor is part of a receptor complex that influences gene expression by binding directly to DNA or interacting with other transcription factors. It regulates genes involved in cell proliferation differentiation and survival. RBP4 on the other hand is part of the serum protein complex responsible for the mobilization of retinol a form of vitamin A ensuring its availability for cellular functions. All-trans retinol acts as a precursor for the synthesis of retinoic acid an important signaling molecule in various biological processes.

Pathways

Estrogen receptor plays a significant role in the MAPK/ERK and PI3K/AKT pathways assisting in cell proliferation and survival. When activated it interacts with other proteins such as HER2 and IGF-1R therefore modulating various cellular responses. RBP4 through its involvement in retinoid metabolism connects with proteins like STRA6 that facilitate retinol uptake into cells. These pathways highlight the interconnectivity of these proteins in maintaining homeostasis and responding to hormonal cues.

Associated diseases and disorders

Both the estrogen receptor and RBP4 have implications in pathological conditions. Mutations or alterations in the estrogen receptor genes are linked to breast cancer where overexpression of ERα can drive cancer progression. RBP4 levels correlate with metabolic disorders such as insulin resistance and type 2 diabetes potentially influencing glucose metabolism. In breast cancer estrogen receptor interactions with proteins like HER2 affect treatment outcomes while in metabolic syndromes RBP4's role with retinoid signaling components such as STRA6 indicates its influence on developing metabolic abnormalities.