Signaling by vitamin A and retinol-binding protein in regulation of insulin responses and lipid homeostasis

► Holo-RBP, which transports vitamin A in blood, is a signaling molecule. ► STRA6 functions both as a vitamin A transporter and as a surface signaling receptor activated by holo-RBP. ► Activation of STRA6 by RBP-ROH triggers a JAK/STAT cascade, thereby inducing gene trascription. ► Some genes induced by RBP-ROH/STRA6/JAK/STAT signaling are involved in regulating insulin responses and lipid metabolism.