Disease relevance of Atp6v1b1

• Urine pH is more alkaline and metabolic acidosis is more severe in Atp6v1b1(-/-) mice after oral acid challenge, demonstrating a failure of normal urinary acidification [1].

High impact information on Atp6v1b1

• Apical expression of the alternative B-subunit isoform, B2, is increased in Atp6v1b1(-/-) medulla and colocalizes with the H(+)ATPase E-subunit; however, the greater severity of metabolic acidosis in Atp6v1b1(-/-) mice after oral acid challenge indicates that the B2-subunit cannot fully functionally compensate for the loss of B1 [1].
• In Atp6v1b1(-/-) mice, the normal urinary acidification induced by a lumen-negative potential in response to furosemide infusion is abolished [1].
• Northern blotting detects a 2.2-kb Atp6v1b1 transcript in the kidney and testis, but not other major organs [2].
• Auditory brainstem response tests revealed normal hearing in mice lacking Atp6b1 [3].
• Our data demonstrate that Atp6b1 is not critical for normal inner ear development or normal inner ear function in mice and suggest that other proton-transporting mechanisms or pH buffering systems must allow the mouse inner ear to compensate for lack of normal Atp6b1 activity [3].

Anatomical context of Atp6v1b1

• Atp6b1 mRNA was first detected at embryonic day 11.5 (E11.5) in the endolymphatic duct epithelia [3].
• From E16.5 onward, Atp6b1 was also observed in the presumptive interdental cell layer of the spiral limbus in the cochlea [3].

Analytical, diagnostic and therapeutic context of Atp6v1b1

• After an acute intracellular acidification, Na(+)-independent pH recovery rates of individual Atp6v1b1(-/-) intercalated cells of the cortical collecting duct are markedly reduced and show no further decrease after treatment with the selective H(+)ATPase inhibitor concanamycin [1].
• Standard in situ hybridization was used for the expression study with routine morphologic and physiologic assessments of hearing and balance in H(+)-ATPase B1 subunit (Atp6b1) null mutant mice [3].

References