Cartoon of the human GMRα subunit intracellular domain mutants. Depicted are motifs that are conserved within the cytokine receptor superfamily. The four spatially conserved cysteines and the WSXWS motif are located within the extracellular domain. A single transmembrane domain is depicted as a line, and the semiconserved proline-rich and VEDE regions are indicated in the intracellular domain. The wild-type hGMRα is 400 amino acids in length. Truncation mutants have a stop codon engineered at the amino acid number indicated. Mutagenesis of the VEDE region (residues 372 through 374) to the sequences VQNQ and VVVV is also depicted.