Prestin in HEK cells is an obligate tetramer.
نویسندگان
چکیده
The unusual membrane motor protein prestin is essential for mammalian hearing and for the survival of cochlear outer hair cells. While prestin has been demonstrated to be a homooligomer, by Western blot and FRET analyses, the stoichiometry of self association is unclear. Prestin, coupled to the enhanced green fluorescent protein, was synthesized and membrane targeted in human embryonic kidney cells by plasmid transfection. Fragments of membrane containing immobilized fluorescent molecules were isolated by osmotic lysis. Diffraction-limited fluorescent spots consistent in size with single molecules were observed. Under continuous excitation, the spots bleached to background in sequential and approximately equal-amplitude steps. The average step count to background levels was 2.7. A binomial model of prestin oligomerization indicated that prestin was most likely a tetramer, and that a fraction of the green fluorescent protein molecules was dark. As a positive control, the same procedure was applied to cells transfected with plasmids coding for the human cyclic nucleotide-gated ion channel A3 subunit (again coupled to the enhanced green fluorescent protein), which is an obligate tetramer. The average step count for this molecule was also 2.7. This result implies that in cell membranes prestin oligomerizes to a tetramer.
منابع مشابه
Prestin in HEK Cells is an 6 Obligate Tetramer 7 8 9
8 9 Richard Hallworth and Michael G. Nichols 10 Department of Biomedical Sciences, Creighton University School of Medicine, 11 Omaha, Nebraska 68178, USA 12 Department of Physics, Creighton University, Omaha, Nebraska 68178, USA 13 14 15 16 17 18 19 20 21 Running Head: Prestin is a Tetramer 22 Corresponding Author: 23 Richard Hallworth 24 Department of Biomedical Sciences 25 Creighton Universit...
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ورودعنوان ژورنال:
- Journal of neurophysiology
دوره 107 1 شماره
صفحات -
تاریخ انتشار 2012