Giorgi D, Bernard J P, Rouquier S, Iovanna J, Sarles H, Dagorn J C
Institut National de la Santé et de la Recherche Médicale, Marseille, France.
J Clin Invest. 1989 Jul;84(1):100-6. doi: 10.1172/JCI114128.
The pancreatic stone protein and its secretory form (PSP-S) are inhibitors of CaCO3 crystal growth, possibly involved in the stabilization of pancreatic juice. We have established the structure of PSP-S mRNA and monitored its expression in chronic calcifying pancreatitis (CCP). A cDNA encoding pre-PSP-S has been cloned from a human pancreatic cDNA library. Its nucleotide sequence revealed that it comprised all but the 5' end of PSP-S mRNA, which was obtained by sequencing the first exon of the PSP-S gene. The complete mRNA sequence is 775 nucleotides long, including 5'- and 3'- noncoding regions of 80 and 197 nucleotides, respectively, attached to a poly(A) tail of approximately 125 nucleotides. It encodes a preprotein of 166 amino acids, including a prepeptide of 22 amino acids. No overall sequence homology was found between PSP-S and other pancreatic proteins. Some homology with several serine proteases was observed in the COOH-terminal region, however. The mRNA levels of PSP-S, trypsinogen, chymotrypsinogen, and colipase in CCP and control pancreas were compared. PSP-S mRNA was three times lower in CCP than in control, whereas the others were not altered. It was concluded that PSP-S gene expression is specifically reduced in CCP patients.
胰石蛋白及其分泌形式（PSP-S）是碳酸钙晶体生长的抑制剂，可能参与胰液的稳定。我们已确定了PSP-S mRNA的结构，并监测了其在慢性钙化性胰腺炎（CCP）中的表达。从人胰腺cDNA文库中克隆了编码前PSP-S的cDNA。其核苷酸序列显示，它包含了PSP-S mRNA除5'端以外的所有部分，5'端是通过对PSP-S基因的第一个外显子进行测序获得的。完整的mRNA序列长775个核苷酸，包括分别为80和197个核苷酸的5'和3'非编码区，后面连接着大约125个核苷酸的poly(A)尾。它编码一个166个氨基酸的前体蛋白，包括一个22个氨基酸的前肽。在PSP-S与其他胰腺蛋白之间未发现整体序列同源性。然而，在COOH末端区域观察到与几种丝氨酸蛋白酶有一些同源性。比较了CCP和对照胰腺中PSP-S、胰蛋白酶原、糜蛋白酶原和辅脂酶的mRNA水平。CCP中PSP-S mRNA比对照低三倍，而其他的没有改变。得出的结论是，CCP患者中PSP-S基因表达特异性降低。
