Control of mu opioid receptor expression by modification of cDNA 5 '- and 3 '-noncoding regions

Removal of a 712 base pair (bp) sequence following the coding region of a h uman mu opioid receptor (h mu OR) cDNA unexpectedly increased expression of the receptor protein. A series of 3'-noncoding region deletion mutants rev ealed that at least three discrete regions following the stop codon influen ced receptor expression levels. Deletion of the 205-bp 5'-noncoding region immediately preceding the Kozak sequence doubled receptor expression relati ve to wild type, and simultaneous deletion of 5'- and 3'-noncoding regions increased expression several fold. The h mu OR noncoding regions may partic ipate in a regulatory mechanism that controls the number of cell surface re ceptors. (C) 2000 Elsevier Science B.V. All rights reserved.