Figure 3.

GTX forms SDS-resistant high molecular weight complexes, and DLG regulates these complexes and is associated with GTX in the body wall muscles. A, Western blot of wild-type and dlg^XI−2 mutant body wall muscle extracts subjected to different temperatures to demonstrate the presence of SDS-resistant high molecular weight complexes and the regulation of some of these complexes by DLG. B, Western blot of wild-type and gtx^ex6 mutant extracts incubated at 42°C in loading buffer. C, Western blot of body wall muscle extracts from wild type, dlg^XI−2, and larvae overexpressing DLG incubated at 42°C in loading buffer. D, Western blot of wild type, overexpression of GTX in a dlg^XI−2 mutant background, and overexpression of GTX in a wild-type background. E, Intensity of the GTX 70 kDa band (A, C, D, arrowhead) observed in dlg mutants and after overexpressing DLG, normalized to wild-type intensity. n = 3 independent Western blots. F, Immunoprecipitation of body wall muscle extracts using anti-DLG antibodies. The blots were sequentially probed with antibodies to GTX, DLG, and Syntaxin-1A. Inputs represent 10% of the extract used for immunoprecipitations. Numbers at the right of the blots represent molecular weights in kDa. The arrow in A–D and F indicates GTX monomer. The arrowhead in A, C, and D indicates the 70 kDa GTX complex. tub, Tubulin; Spec, Spectrin; IP, immunoprecipitation.