When a certain protein in human muscle cells is blocked, insulin can't turn on or move a key cellular pump that helps muscles work properly.

Insulin helps move certain proteins to the surface of human muscle cells and boosts their activity, and this seems to involve a specific cellular signaling process.

When insulin acts on human muscle cells, it turns on a switch (ERK1/2) that helps modify a specific protein (the sodium-potassium pump) at certain spots—this has been seen in lab tests using drugs and purified enzymes.

When you eat, your body releases insulin, which helps muscle cells pull more potassium from your blood by putting more pumps on their surface—this keeps your muscles working smoothly after meals.

When rats are given insulin, a specific part of a pump in their muscle cells moves from inside the cell to the outer membrane, but another similar part stays where it is.

When insulin is present, certain parts of a pump in rat muscle cells move to the surface of the cell—these parts work together like a team that responds to insulin.