The identification of novel locations for the a4 subunit and other tissue-restricted subunits increases the range of unique subunit combinations making up the proton pump.
V-ATPase a4 knockout mice suffer not only from severe acidosis but also from proximal tubule dysfunction with defective endocytic trafficking proteinuria phosphaturia and accumulation of lysosomal material.
Data suggestthat Foxi1 is necessary for expression of at least four subunits in three different epithelia and most likely is a major determinant for proper assembly of a functional vacuolar H(+)-ATPase complex at these locations.
Immunolocalization demonstrated expression of all 'a' subunits in the proximal tubule and in the intercalated cells of the collecting system. PCR detected mRNAs encoding all four 'a' isoforms with a relative abundance in the following order: a4>a2=a1>a3.
We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.