Transmembrane 4 L6 family member 20 (TM4SF20)

Transmembrane 4 L6 family member 20 (TM4SF20) is a membrane protein belonging to the four-transmembrane L6 superfamily, characterized by four transmembrane domains and broad tissue expression, including high levels in regions of the human brain such as the parietal and occipital lobes, hippocampus, pons, white matter, corpus callosum, and cerebellum[3][7]. TM4SF20 is the first protein shown to undergo regulated alternative translocation (RAT), a process induced by ceramide that inverts the topology of the protein within the endoplasmic reticulum membrane[1][4][5]. This topological change regulates the ability of TM4SF20 to inhibit or stimulate the proteolytic activation of the membrane-bound transcription factor CREB3L1, thus modulating the induction of genes involved in collagen synthesis and cell proliferation[1][2][3][6]. Knockout of the homologous gene in mice results in alterations in neurobehavioral phenotypes, including enhanced motor coordination, and human gene deletion has been linked to specific language impairment[3]. TM4SF20 does not have a well-documented direct therapeutic targeting role, known small molecule ligands, or use as a biomarker, and no notable safety or toxicity issues have been described in the available literature.

Other names

Transmembrane 4 L6 family member 20TM4SF20UNQ518/PRO994FLJ22800TCCE518PRO994SLI5