Figure 1.

Comparison of amino acid sequences of three membrane-spanning proteins: Sterol-regulatory element-binding protein 1 (SREBP-1), amyloid precursor-like protein 2 (APLP2), and the amyloid precursor protein (APP). The numbering above the APP sequence refers to the codon corresponding to the position in the holoprotein. The numbering below the APP sequence refers to the amino acid position beginning with Asp-1 of the Aβ peptide. Known disease-causing mutations of APP are shown below the sequence and their tendency to increase (↑) either total Aβ or Aβ₄₂ is noted. Intramembranous cleavage sites are noted as site 2 in SREBP and as the γ cuts in APP.