In vitro binding assays.

A fragment (amino acids 1697-2102) of NuMA C-terminal region was tested in vitro for its binding to the CTDs of 4.1R, CO.1, CO.2, or 4.1G. (A) Coomassie blue detection of 4.1R (1), CO.1 (2), CO.2 (3), and 4.1G (4). M indicates molecular size markers (kDa). (B) Autoradiography of radiolabeled NuMA. NuMA bound to 4.1R and 4.1G (1 and 4), but not to either CO.1 or CO.2 (2 and 3). Nu: appearance of NuMA alone following the in vitro coupled transcription/translation reaction.