When inserting surface receptors into the somatodendritic plasma membrane, neurons have a choice. Their decision determines how long receptors linger at the point of insertion, as shown by Guillermo Yudowski, Manojkumar Puthenveedu, and Mark von Zastrow (University of California, San Francisco, CA).
The number of receptors in the plasma membrane largely determines neuronal sensitivity to signaling molecules. Although the removal of activated receptors has been widely studied, their replacement has been a less popular topic. “Historically, most people thought of it as simply a bulk-flow process,” says van Zastrow. “The bias in the field, and one that I held, honestly, is that insertion processes would be unregulated.”
The UCSF group has now, however, identified two distinct types of insertion events—both regulated. In the predominant type, GFP-tagged β2 adrenergic receptors (β2ARs) moved laterally away from the insertion site almost immediately. In the second, the receptors were...
