Disease relevance of Slc4a7

• Mice lacking NBC3 develop blindness and auditory impairment because of degeneration of sensory receptors in the eye and inner ear as in Usher syndrome [1].
• Mice with a targeted disruption of the gene encoding the stilbene-insensitive electroneutral sodium bicarbonate cotransporter (NBC3; slc4a7) exhibit cochlear and retinal degeneration [2].

High impact information on Slc4a7

• Our data indicate that the USH2 proteins and NBC3 are further partners in the supramolecular USH-protein network in the retina and inner ear which shed new light on the function of USH2 proteins and the entire USH-protein network [3].
• Precipitation of NBC3 or CFTR from transfected HEK293 cells and from the pancreas and submandibular gland also coimmunoprecipitated EBP50 [4].
• Notably, the acinar cell NBC3 variants transported HCO3- but not OH(-) [5].
• Functional and immunocytochemical localization of these activities in the perfused duct indicated that pNBC1 probably mediates the DIDS-sensitive/EIPA-insensitive transport in the basolateral membrane, and splice variants of NBC3 probably mediate the DIDS-insensitive/EIPA-sensitive NBC activity in the LM of duct and acinar cells [5].
• Hence, we propose that the SLC4A10 gene product and NBCn1 both function as basolateral HCO3- entry pathways and that the SLC4A10 gene product may be responsible for the stilbene-sensitive Na+-HCO3- uptake that is essential for cerebrospinal fluid production [6].

Biological context of Slc4a7

• Intact mouse mesenteric small arteries were electropermeated to facilitate transfection with small interfering RNA targeting NBCn1, which resulted in an approximate 43% decrease in the ratio of NBCn1 to glyceraldehyde-3-phosphate dehydrogenase mRNA [7].
• Knockout mice for AE2 and NBCn1 do not have obvious renal phenotypes [8].

Anatomical context of Slc4a7

• Furthermore, the stilbene-insensitive Na+-HCO3- cotransporter, NBCn1, was also localized to the basolateral plasma membrane domain of the choroid plexus epithelium [6].
• Damage of the sensory epithelia at the high frequency zone of the cochlea suggests that NBC3 may play an important physiological role in this region [2].
• NBC3 mild immunoreactivity was detected in the organ of Corti at P11 [2].
• We conclude that NBCn1 mediates the Na+-dependent bicarbonate transport important for pH(i) regulation in smooth muscle cells of mouse mesenteric, coronary, and cerebral small arteries [7].
• NBCn1 (slc4a7) mediates the Na+-dependent bicarbonate transport important for regulation of intracellular pH in mouse vascular smooth muscle cells [7].

Other interactions of Slc4a7

• From P21 to P90, NBC3 expression was confined to the spiral ligament and inner and outer sulcus cells [2].

Analytical, diagnostic and therapeutic context of Slc4a7

• The time course of NBC3 expression in the cochlea was assessed by immunohistochemistry using an antibody against NBC3 [2].
• RT-PCR analyses showed that NBCn1 (slc4a7) is the only Na+-dependent bicarbonate transporter of the slc4 family detectable at the mRNA level in all 3 vascular beds investigated [7].
• Whole-mount immunolabeling and immunogold electron microscopy confirmed the presence of NBCn1 protein in the sarcolemma of mouse mesenteric small arterial smooth muscle cells [7].

References