Relationship between fluorescence intensity of GFP and the expression level of prestin in a prestin-expressing Chinese hamster ovary cell line

Abstract

Outer hair cells (OHCs) in mammals can elongate and contract at frequencies up to 100 kHz in response to changes in their membrane potential. The origin of this unique motility is the motor protein prestin, which is densely packed in the lateral membrane of the OHCs. In a previous work, we constructed a prestin-expressing cell line using Chinese hamster ovary (CHO) cells to obtain a stable supply of prestin. When we research prestin using constructed cells, it is necessary to estimate the expression level of prestin in the cells easily and noninvasively. As the prestin gene and a green fluorescent protein (GFP) gene were introduced into constructed cells using the same vector, the expression level of prestin and fluorescence intensity of GFP are possibly correlated. Since this correlation is not clear, however, in this study, we therefore investigated whether the expression level of prestin evaluated by patchclamp recording and the fluorescence intensity of GFP obtained from fluorescence images are correlated or not. As a result, it was demonstrated that they were correlated. The expression level of prestin can therefore be evaluated by measuring the fluorescence intensity of GFP.