Details

Autor(en) / Beteiligte

• Gong, Wenrong
• Gong, Xiaoming
• Zaripheh, Susan
• Zarkhin, Eli
• Rubin, Lewis

Titel

Identification of a transdominant negative splice variant of b ‐Carotene 9′,10′‐monoxygenase

Ist Teil von

• The FASEB journal, 2007-04, Vol.21 (5), p.A354-A354

Ort / Verlag

Federation of American Societies for Experimental Biology

Erscheinungsjahr

2007

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Introduction: Retinoic acid (RA) is critical for mammalian reproduction, embryonic development, growth, epithelial differentiation, vision and the immune response. Various pro‐vitamin A and other carotenoids have less well described tissue‐specific functions. b‐Carotene 9′,10′‐monoxygenase (CMO2) is an alternative enzymatic pathway for metabolizing provitamin A carotenoids into RA and metabolizing the non‐provitamin A carotenoid, lycopene. Serum lycopene levels have been inversely associated with the risk of prostate cancer and cardiovascular disease. Our laboratory and others have suggested CMO2 is may be a key mediator of lycopene metabolism and activity. We hypothesize that this enzyme pathway may be important in tumor cell sensitivity to lycopene. The objectives of this study were: to characterize CMO2 gene expression in various human cell lines and tissues, and to determine the expression and identify the function of spliced form CMO2. Methods: Using RT‐PCR, we investigated CMO2 expression in human liver HepG2 cells. A spliced form of CMO2 which lacks exon 6,7,8 was identified. We cloned this spliced form and used Western‐blot analysis to confirm its protein expression. Results: We found CMO2 mRNA is expressed as different spliced forms in HepG2 cells. A spliced form which lacks 3 exons compared with the full length CMO2 was sequenced. The expression of this spliced form CMO2 was confirmed in several prostate cell lines. We cloned this splice variant as well as full length CMO2 in a bacterial expression vector as fusion protein. Protein expression was confirmed by Western‐blot. In an E Coli testing system, we demonstrated this splice valiant has trans‐dominant negative activity for CMO2 metabolism of lycopene. (NIH HD42174, RR18728).