Words similar to beta-
Example sentences for: beta-
How can you use “beta-” in a sentence? Here are some example sentences to help you improve your vocabulary:
There are three subtypes of the alpha-2 adrenergic receptor: alpha-2A; alpha-2B; and alpha-2C [ 15 ] . The human alpha-2A subtype undergoes phosphorylation and short-term desensitization [ 11 12 ] , whereas the human alpha-2C subtype is not phosphorylated [ 16 ] and does not desensitize [ 11 ] . The human alpha-2C subtype, however, does undergo arrestin-dependent internalization [ 17 ] . Many studies [ 11 18 ] , including those from our laboratory [ 10 19 20 ] , have demonstrated agonist-induced down-regulation of alpha-2 receptors, although much less is known about the specific mechanisms for down-regulation as compared to the beta-2 receptor.
Desensitization occurs both in cell culture systems [ 10 11 12 ] and in the intact animal [ 13 14 ] . In general the mechanisms of desensitization for the alpha-2 adrenergic receptors appear to be similar to those for the beta-2 receptor.
Initial uncoupling of the beta-2 receptor from the G protein after agonist binding is mediated by phosphorylation by G protein-coupled receptor kinase (GRK) of specific residues in the carboxyl tail of the receptor.
The phosphorylated beta-2 receptor enhances the binding of beta-arrestin, which not only uncouples the receptor from the signal transduction process but also serves as an adapter protein that mediates entry into the internalization pathway [ 5 ] , as well as serving as a platform for additional signaling pathways [ 6 ] . The mechanisms of beta-2 adrenergic receptor down-regulation appear to involve both an increase in the rate of degradation of the receptor as well as a decrease in the levels of beta receptor mRNA [ 7 ] . Down-regulation of the beta-2 receptor is, in part, due to trafficking of the beta-2 receptor to lysosomes via the clathrin-coated pit endosomal pathway [ 8 9 ] .
Down-regulation occurs after prolonged agonist treatment (hours to days), resulting in a loss of receptor binding sites [ 2 3 4 ] . The processes involved in homologous desensitization have been extensively investigated for the beta-2 adrenergic receptor, which is the prototypical G protein-coupled receptor.
Loading...