A set of homo-oligomeric standards allows accurate protein counting.
Techniques based on fluorescence microscopy are increasingly used to count proteins in cells, but few stoichiometrically well-defined standards are available to test their accuracy. A selection of bacterial homo-oligomers were developed that contain 10-24 subunits and fully assemble when expressed in mammalian cells, and they can be used to easily validate/calibrate molecular counting methods. The utility of these standards was demonstrated by showing that nuclear pores contain 32 copies of the Nup107 complex.
Single Molecule Biophysics, Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany). kieran.finan.13@ucl.ac.uk.|Current address: UCL Medical School, Gower St., London (UK). kieran.finan.13@ucl.ac.uk.
Kieran
K
Finan
Single Molecule Biophysics, Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany).
Anika
A
Raulf
Single Molecule Biophysics, Institute for Physical and Theoretical Chemistry, Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt am Main (Germany). heilemann@chemie.uni-frankfurt.de.
Mike
M
Heilemann
D001426:Bacterial Proteins / Q000032:analysis*; D002460:Cell Line; D004926:Escherichia coli / Q000737:chemistry*; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods*; D022022:Nuclear Pore / Q000737:chemistry*; D028861:Nuclear Pore Complex Proteins / Q000032:analysis*; D046940:Synechococcus / Q000737:chemistry*
D001426:Bacterial Proteins; C512772:NUP107 protein, human; D028861:Nuclear Pore Complex Proteins
fluorescence microscopy; nuclear pores; protein counting; proteins; super-resolution imaging