A method of reducing blood glucose in a subject has been developed. In preferred embodiments, the method involves administering to the subject a specific activator of endogenous mitogen-activated protein kinase kinase 6 (MKK3), mitogen-activated protein kinase kinase 6 (MKK4), mitogen-activated protein kinase kinase 6 (MKK6), p38 mitogen-activated protein kinase (p38MAPK), mitogen-activated kinase-activated protein kinase 2 (MK2), or a combination thereof, in an effective amount to reduce blood glucose in a subject. In other embodiments, the method involves administering to the subject a specific activator to increase X-box binding protein 1 (XBP1) phosphorylation on Thr48 and Ser61 in an effective amount to reduce blood glucose in the subject. Methods of identifying agents for reducing blood glucose in a subject are also provided.