In:
American Journal of Physiology-Renal Physiology, American Physiological Society, Vol. 273, No. 5 ( 1997-11-01), p. F801-F806
Abstract:
Chronic restriction of dietary P i elicits an increased reabsorption of P i in the kidney proximal tubules, which involves a stimulation of apical Na-P i cotansport. This adaptation is in part a direct cellular response of which the mechanism(s) are poorly understood. In this study, the impact of dietary P i restriction on the differential expression of rat kidney cortex mRNAs was visualized to identify gene products regulated by the P i status. When kidney cortex mRNAs of rats fed a low- or a high-P i diet were compared by differential display-polymerase chain reaction (DD-PCR), thirty modulated cDNA bands were observed, of which four were confirmed as being regulated. We focused on one of the upregulated bands, dietary P i -regulated RNA-1 (diphor-1). A cDNA containing an open reading frame encoding a 52-kDa protein was cloned by library screening. Diphor-1 exhibits a high degree of identity to the Na/H exchanger regulatory factor and to a tyrosine kinase activating protein. Highest expression of diphor-1 mRNA was detected in the kidney (proximal tubules) and in small intestine. Expression experiments showed that diphor-1 specifically increases Na-P i cotransport in oocytes of Xenopus laevis coinjected with renal type II Na-P i cotransporter cRNA. Further characterizations of diphor-1 will show whether diphor-1 is primarily or secondarily involved in the response to dietary P i .
Type of Medium:
Online Resource
ISSN:
1931-857X
,
1522-1466
DOI:
10.1152/ajprenal.1997.273.5.F801
Language:
English
Publisher:
American Physiological Society
Publication Date:
1997
detail.hit.zdb_id:
1477287-5
