High impact information on FXYD2

• It is suggested that structural association of the TM regions of alpha and FXYD 2 is not the sole determinant of this effect of FXYD on KNa' but is subject to long range modulation by the extramembranous L7/8 loop of alpha [1].
• Sodium and potassium-exchanging adenosine triphosphatase (Na,K-ATPase) in the kidney is associated with the gamma subunit (gamma, FXYD2), a single-span membrane protein that modulates ATPase properties [2].
• Isolated hereditary renal magnesium (Mg) wasting may result from mutations in the renal tubular epithelial cell tight junction protein paracellin-1 gene or the tubular Na(+),K(+)-ATPase gamma-subunit gene FXYD2 [3].
• The defective FXYD2 gene in these families mapped to chromosome 11q23 [3].
• The FXYD2 gene was implicated in autosomal dominant renal Mg(2+) wasting associated with hypocalciuria [4].

Biological context of FXYD2

• In the FXYD2 gene, there are two closely spaced polyadenylation signals, and both are used [5].
• RESULTS: The phenotype of the new family closely resembles that of the known dominant families with a mutation in FXYD2, but mutations in this gene were not identified in the new family [4].
• In addition, haplotype analysis excluded linkage to the FXYD2 region on chromosome 11q23 [4].
• FXYD2 is on chromosome 11q23 close to a site of tumorigenic chromosomal translocations, and has a number of repeat elements [5].
• Although the gamma subunit of the Na,K-ATPase has only 66 or 68 amino acids, its human gene (FXYD2) was found to span 9.2 kb and have seven exons, including two alternatively spliced exons encoding different N-termini [5].

Anatomical context of FXYD2

• A marked induction of metallothioneins as well as ATP1G1 transcripts was detected in all patient cell lines [6].

Other interactions of FXYD2

• Moreover, a mutation in FXYD2 has been linked to cases of human hypomagnesemia, indicating that perturbations in the regulation of Na-K-ATPase by FXYD proteins may be critically involved in pathophysiological states [7].

References