Rhesus glycoprotein homologs RhAG, RhBG, and RhCG comprise a recently identified branch of the Mep/Amt ammonia transporter family. Animal studies have shown that RhBG and RhCG are present in the kidney distal tubules. Studies in mouse and rat tissue suggest a basolateral localization for RhBG in cells of the distal tubules including the alpha-intercalated cells (alpha-IC), but no localization of RhBG has been reported in human tissue.
View Article and Find Full Text PDFAn important question in renal physiology is how the alpha-intercalated cells of the kidney regulate the distribution of the basolateral kidney anion exchanger 1 (kAE1) according to systemic acid-base status. Previous work using a MDCKI model system demonstrated that kAE1 basolateral targeting requires an N-terminal determinant and a critical C-terminal tyrosine (Y904). Here, we show that the N-terminal determinant is residue Y359, because a Y359A substitution mutant was mistargeted to the apical membrane.
View Article and Find Full Text PDFThe gas vesicles of the cyanobacterium Anabaena flos-aquae contain two main proteins: GvpA, which forms the ribs of the hollow cylindrical shell, and GvpC, which occurs on the outer surface. Analysis by MALDI-TOF MS shows that after incubating Anabaena gas vesicles in trypsin, GvpA was cleaved only at sites near the N-terminus, whereas GvpC was cleaved at most of its potential tryptic sites. Many of the resulting tryptic peptides from GvpC remained attached to the underlying GvpA shell: the pattern of attachment indicated that there are binding sites to GvpA at both ends of the 33-residue repeats (33RRs) in GvpC, although one of the tryptic peptides within the 33RR did not remain attached.
View Article and Find Full Text PDFWe present data on a patient of South Asian origin with recessive hereditary spherocytosis (HS) due to absence of protein 4.2 [4.2 (-) HS].
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