SID1 transmembrane family member 1 (SIDT1)

SID1 transmembrane family member 1 (SIDT1) is a membrane protein composed of 11 transmembrane segments, forming functional homodimers at the plasma membrane. Structurally and functionally related to its C. elegans homolog SID-1, SIDT1 enables uptake of dsRNA and dietary miRNAs, especially under low pH conditions, facilitating systemic RNA interference and posttranscriptional gene silencing. In addition to its RNA transport function, SIDT1 possesses ceramidase enzyme activity, tightly regulated by its interactions with cholesterol via conserved CRAC domains. Cholesterol binding causes conformational changes that modulate lipid hydrolytic activity. SIDT1 is implicated in immune response, tumorigenesis, and chemoresistance (notably involving microRNA-21 in cancer cells). It interacts with RNA and lipid molecules, but no direct pharmacological inhibitors or activators have yet been clinically detailed.

Other names

SIDT1SID1FLJ20174SID1 transmembrane family member 1SID-1

Facilitation of dsRNA/miRNA/siRNA cellular uptake (energy-independent dsRNA transport); Lipid hydrolytic activity modulated by cholesterol binding (ceramidase activity sensitive to allosteric cholesterol regulation)