Arrestin-1 expression level in rods: balancing functional performance and photoreceptor health

▶Mice expressing arrestin-1 at the levels from 4% to 220% of wild type were tested. ▶Arrestin-1 content in dark-adapted outer segment exceeds earlier estimates. ▶High arrestin-1 expression slightly improves rod performance. ▶Very low arrestin-1 expression is sufficient for rod function in dim light. ▶Low arrestin-1 concentration in the outer segment slows down photoresponse recovery.