Family with sequence similarity 243 member B (FAM243B)

The molecule referred to as ENSG00000277277, also known as FAM243B, protein FAM243B, uncharacterized protein C21orf140, LOC102723451, is currently poorly characterized and does not have evidence supporting its role as a therapeutic target or a clear biological function. No firmly established biological functions. It is expressed across many tissues, including male germ line stem cells in testis[3], and may have roles in lysosomal and endoplasmic reticulum function, but this is speculative and not supported by phenotype data in knockout models[1][5]. No established role in disease; human variant p.Val115Gly was identified in a patient with developmental delay, but lysosome morphology was normal and no disease-association has been confirmed[5]. No drugs are known to interact with this target. No recognized mechanisms of drug action. Not established as a biomarker for any condition. No safety concerns or therapeutic challenges have been described. Family with sequence similarity 243 member B (FAM243B) is a small, widely expressed human protein (121 amino acids) containing a conserved domain of unknown function (DUF4605, pfam15378)[1][5]. It is evolutionarily ancient and shows some sequence similarity to yeast proteins, but its molecular and physiological function in vertebrates remains undetermined. FAM243B (and its paralog FAM243A) are distributed in lysosomes and the endoplasmic reticulum according to localization studies. Mouse knockout models for Fam241a and Fam241b (the mouse orthologs) display no overt phenotype, normal growth, fertility, and lifespan even in double knockouts, suggesting no essential function detectable under standard conditions[1][5]. In humans, the gene is expressed in a broad range of tissues, including male germ line stem cells in the testis[3]. No disease associations, known drug interactions, or descriptive molecular pathways have been established to date. FAM243B is an evolutionarily conserved, uncharacterized protein with no known physiological roles, disease associations, or established classification as a therapeutic target. It is best categorized as an "Other/Uncharacterized protein" pending future research on its function and potential disease relevance.

Other names

FAM243Bprotein FAM243Buncharacterized protein C21orf140LOC102723451ENSG00000277277