Decreased sulfotransferase SULT1C2 gene expression in DPT-induced polycystic kidney.
BACKGROUND
The pathogenesis of polycystic kidney disease (PKD) remains unclear despite the identification of the genes responsible for hereditary PKD. In this study, we investigated the alteration of gene expressions in an acquired PKD model induced by 2-amino-4,5-diphenylthiazole (DPT) using the differential display method.


METHODS
Kidney mRNA from a Sprague-Dawley rat fed with 1% DPT for 4 days and from a control rat was compared by the RT-PCR differential display method. Differentially expressed bands were re-amplified and subcloned. Using these subclones as probes, the changes in gene expressions were confirmed by Northern blot analysis. Subsequently, mouse kidney cDNA library was screened.


RESULTS
The isolated 1.5-kb cDNA contained an open reading frame encoding 296 amino acids, which shared 94.3% identity with rat SULT1C2 sulfotransferase, and was considered to be its mouse ortholog (GenBank Accession No. AY005469). Mouse SULT1C2 mRNA was abundant in the kidney and stomach among normal mouse tissues. The expression of SULT1C2 mRNA was decreased in the rat kidney after DPT feeding but not in the stomach. Mouse SULT1C2 was expressed successfully using pET plasmid vector and E. coli. The recombinant 34-kD protein was capable of catalyzing the sulfation of p-nitrophenol at a Km of 3.1 mmol/L, by utilizing 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as the sulfate donor.


CONCLUSIONS
Although the physiological substrate and function of SULT1C2 have yet to be elucidated, its down-regulation could be involved in the cystic changes of tubules by decreasing the sulfation of the tubular basement membrane components.
Sugimura
Kazunobu
K
Department of Urology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan. ksugimura@msic.med.osaka-cu.ac.jp
Tanaka
Tomoaki
T
Tanaka
Yoshihiko
Y
Takano
Haruna
H
Kanagawa
Kenji
K
Sakamoto
Nobuyoshi
N
Ikemoto
Shin-Ichi
S
Kawashima
Hidenori
H
Nakatani
Tatsuya
T
D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D020869:Gene Expression Profiling; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D007690:Polycystic Kidney Diseases / Q000139:chemically induced / Q000201:enzymology* / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015238:Sulfotransferases / Q000235:genetics*; D013844:Thiazoles
D018076:DNA, Complementary; D013844:Thiazoles; C002886:Bax 439; D015238:Sulfotransferases; C513318:Sult1c2 protein, mouse; C513315:Sult1c2 protein, rat