Transcription factor that specifically recognizes and binds E-box sequences (3'-CANNTG-5'). Efficient DNA-binding requires dimerization with itself or with another MiT/TFE family member such as TFE3 or MITF. In association with TFE3, activates the expression of CD40L in T-cells, thereby playing a role in T- cell-dependent antibody responses in activated CD4(+) T-cells and thymus-dependent humoral immunity. Specifically recognizes and binds the CLEAR-box sequence (5'-GTCACGTGAC-3') present in the regulatory region of many lysosomal genes, leading to activate their expression. It thereby plays a central role in expression of lysosomal genes. Specifically recognizes the gamma-E3 box, a subset of E-boxes, present in the heavy-chain immunoglobulin enhancer. Plays a role in the signal transduction processes required for normal vascularization of the placenta. Homodimer and heterodimer; with TFE3 or MITF. Belongs to the MiT/TFE family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Biological Process: embryonic placenta development; humoral immune response; lysosome organization and biogenesis; positive regulation of autophagy; positive regulation of transcription from RNA polymerase II promoter