PFKM and distal renal tubular acidosis: In human renal cells, PFK-1 binds the C-terminus of the V-ATPase Vo subunit a isoform a4 (Voa4-CT); naturally occurring genetic mutations disrupt Voa4-CT association with PFK-1 and cause recessive distal renal tubular acidosis (Su et al., 2003, 2008).