 Similarly, reducing the expression of LRAT also decreased the ability of RBP-ROH complex to phosphorylate JAK2 and STAT5.Therefore, both CRBP-I and LRAT are necessary for the STRA6 signaling cascade upon the binding and transport of retinol.JAK2 is also conversely responsible for the activation of STRA6, after which apo-CRBP-I is recruited to the intercellular CBL of STRA6 and vitamin A might be transferred by the receptor to CRBP-I.