The researchers found that when they dosed cells that expressed a2C-AR with chemicals that activate Rap1A, either directly or through means that involve another protein called Epac, the cells drew from pools of a2C-AR near the cell's nucleus and moved these receptors to the cell surface. The series of events involved rearrangment of the cell's internal "skeleton," fibers that determine its shape and can transport items from one area of a cell to another.
Importance of the Findings and What Part of Cell Physiology Gets 'The Rap'
Authors of the study and the accompanying editorial suggest that the series of events and biological interactions they identified could be responsible for the mechanism the body uses to limit blood supply to the skin in cold temperatures, which conserves more blood flowand hence, warmthfor the body's internal organs. The findings may provide clues to where dysfunction occurs in disorders in which blood flow is erroneously cut off, such as Raynaud's disease. In this condition, sufferers lose circulation to the fingers, toes, and occasionally other areas when the body overreacts to cold temperatures. Raynaud's can sometimes be serious, leading to atrophy of skin and muscle, ulceration and rarely to ischemic gangrene. On a lighter note, the results also provide a possible explanation for the age-old problem of cold feet.
"Thus, if your partner complains again about your cold feet," the editorial authors write, "you have some new excuses: 'It's Epac's fault!' or 'Rap1A should get the rap!'"
|Contact: Donna Krupa|
American Physiological Society