Figure 5.

Schematic representation of a2-a4 subunits and location of mutations with the corresponding diseases. Besides a1, there are 3 other isoforms of V-ATPase subunit a. Various mutations have been reported in different diseases. Key mutations that are heavily discussed in the text are bolded and underlined. (A) Locations of various mutations to the a2 subunit, identified in cases of autosomal recessive cutis laxa type II (ARCL II). Amino acid sequences are based on Q9Y487 in UniProt. (B) Locations of identified mutations to the a3 subunit contributing to malignant infantile osteopetrosis (MIOP) (red) and its milder form (yellow). Amino acid sequences are based on Q13488 in UniProt. (C) Locations of mutations to the a4 subunit involved in distal renal tubular acidosis (dRTA). Amino acid sequences are based on Q9HBG4 in UniProt. For the purpose of annotation, transmembrane helices α₇-α₈ are not tilted. The figure was created with BioRender.com.