[5][6] The protein encoded by this gene is a regulator of the pancreatic beta-cell function.

It is highly similar to JIP-1, a mouse protein known to be a regulator of c-Jun amino-terminal kinase (Mapk8).

This protein has been shown to prevent MAPK8 mediated activation of transcription factors, and decrease IL-1 beta and MAP kinase kinase 1 (MEKK1) induced apoptosis in pancreatic beta cells.

This protein also functions as a DNA-binding transactivator of the glucose transporter GLUT2.

RE1-silencing transcription factor (REST) is reported to repress the expression of this gene in insulin-secreting beta cells.