Transmembrane neural differentiation-associated intracellular calcium regulator (TUNAR)

Transmembrane neural differentiation-associated intracellular calcium regulator (TUNAR) is a gene originally annotated as a long non-coding RNA (lncRNA) but now known to encode a small transmembrane microprotein (pTUNAR/BNLN) of 48 amino acids, highly conserved in vertebrates[1][2][3]. TUNAR is predominantly expressed in the central nervous system, specifically in neurons and newly formed oligodendrocytes, as well as in pancreatic beta cells[1][3][5]. At the molecular level, pTUNAR localizes to the endoplasmic reticulum membrane and interacts directly with the SERCA2 and SERCA3 calcium transporters, modulating calcium exchange between the endoplasmic reticulum and cytosol[1][2][5]. Functionally, pTUNAR overexpression impairs neuronal differentiation and neurite formation by reducing cytoplasmic calcium, while its deficiency promotes neural lineage differentiation[1][2][5]. In pancreatic beta cells, it lowers ER Ca^2+ levels and enhances glucose-stimulated insulin secretion[5]. TUNAR and its protein product are implicated in neurodevelopmental processes, diabetes, and are dysregulated in diseases such as glioblastoma and Huntington's disease[1][5]. Currently, TUNAR is not established as a direct therapeutic target (e.g., by existing drugs), but its emerging functional roles highlight potential biomedical significance in neurobiology and metabolic disorders[1][2][5].

Other names

TCL1 upstream neural differentiation-associated RNATUNAR lncRNAbeta cell- and neural cell-regulinTUNApTUNARBNLNHI-LNC78Human islet long non-coding RNA 78LINC00617Protein TUNARTcl1 upstream neuron-associated lincRNAlong intergenic non-protein coding RNA 617