Two important signaling proteins called AMPK and CaMKII turn on the GLUT4 gene by modifying how tightly DNA is packed, making it easier for the cell to read the gene instructions and produce more GLUT4 protein.

The study confirms that AMPK and CaMKII are the key kinases that control GLUT4 protein production in muscle cells by activating the HDAC4/5-MEF2 pathway, leading to changes in gene packaging that turn on the GLUT4 gene. This matches exactly what the claim describes.