FLVCR1

FLVCR1 (Feline Leukemia Virus Subgroup C Receptor 1) is a protein in humans encoded by the FLVCR1 gene. It functions primarily as a heme exporter, playing a crucial role in erythropoiesis (red blood cell production) and iron homeostasis.

Function:

FLVCR1 is a transmembrane protein responsible for transporting heme out of cells. This is particularly important in erythroblasts (precursors to red blood cells) during the final stages of maturation. Heme is a porphyrin ring containing iron, essential for the function of hemoglobin in red blood cells. When red blood cells mature and lose their mitochondria, excess heme needs to be removed to prevent toxicity. FLVCR1 facilitates this process by exporting heme across the cell membrane. It also functions in other cells for heme homeostasis. The protein has also been implicated in playing a role in cellular resistance to certain viral infections.

Gene:

The FLVCR1 gene is located on human chromosome 1q32.1. Different isoforms of the protein can be produced through alternative splicing of the FLVCR1 gene, leading to variations in the protein's function and localization.

Clinical Significance:

Mutations in the FLVCR1 gene are associated with various human diseases, including:

• Diamond-Blackfan Anemia (DBA): Some atypical forms of DBA, a rare inherited bone marrow failure syndrome, are caused by mutations in FLVCR1. These mutations impair heme export, leading to heme accumulation and toxicity in erythroblasts, resulting in impaired red blood cell production.
• Posterior Column Ataxia with Retinitis Pigmentosa (PCARP): Certain mutations in FLVCR1 can cause PCARP, a neurodegenerative disorder characterized by progressive ataxia (loss of coordination) and retinitis pigmentosa (degeneration of the retina). The exact mechanisms by which FLVCR1 mutations lead to PCARP are still under investigation, but they likely involve heme-related toxicity in neuronal and retinal cells.

Structure:

FLVCR1 is predicted to have 12 transmembrane domains, a characteristic of many transporter proteins. The structure of the protein, particularly the heme-binding site and the mechanism of heme transport, are areas of ongoing research.

Interactions:

FLVCR1 has been shown to interact with other proteins involved in heme metabolism and cellular transport. Further research is aimed at elucidating the full network of protein interactions involving FLVCR1 and its role in various cellular processes.