Predominant presence of β-arrestin-1 in small sensory neurons of rat dorsal root ganglia

Reverse transcription-polymerase chain reaction and western immunoblot analyses were performed to demonstrate the presence of β-arrestin-1 in rat dorsal root ganglion. β-Arrestin-1 existed as two alternatively spliced variants, although predominantly in its untruncated form. Several factors affected the visualization of the truncated version on a sodium dodecyl sulfate-polyacrylamide gel; however, the isoform was clearly detected on a two-dimensional gel. We further localized β-arrestin-1 immunoreactivity in the sensory neurons of the 5th lumbar dorsal root ganglia. β-arrestin-1-immunoreactive neurons accounted for ~60% of the sensory neurons, and ~88% of the β-Arrestin-1 immunoreactive neurons fell into a category of small neurons having a diameter of 10-30μm.Members of the arrestin superfamily play crucial roles in the desensitization of G protein-coupled receptors. Our data demonstrating the presence of β-arrestin-1 in the rat dorsal root ganglion at both messenger RNA and protein levels support the idea that β-arrestin-1 participates in receptor desensitization in the sensory neurons. Furthermore, because small-size neurons of dorsal root ganglion are often implicated in nociception, the predominant presence of β-arrestin-1 immunoreactivity in small-size sensory neurons suggests that β-arrestin-1 may have a role modulating nociceptive signals. Copyright (C) 1999 IBRO.