Fig. 1. The transmembrane and juxtamembrane domains of CD98 are highly conserved. (A) Amino acid sequences of the cytoplasmic, transmembrane and proximal extracellular domains of the human, mouse, hamster, zebrafish (DR) and Drosophila (DM) CD98 protein or CD98 homologs. Zebrafish and human CD98 had 44 identical amino acids out of 47 (94%) in the transmembrane and juxtamembrane domains but only 32% identity for the rest of the protein (data not shown). (B) The sequence of the Drosophila homolog accession number AY070626 was compared to the human CD98 sequence at 10-amino acid intervals utilizing alignment software MultAlin (Corpet, 1988). The percentage of sequence similarity was plotted on the y axis and the amino acid number on the x axis.