Imai A, Nashida T, Shimomura H
Department of Oral Biochemistry, Nippon Dental University, School of Dentistry at Niigata, Japan.
Biochem Mol Biol Int. 1996 Dec;40(6):1175-81. doi: 10.1080/15216549600201813.
In previous reports, we have shown that cAMP-specific phosphodiesterase (PDE4) is the major PDE in the rat parotid gland, and that PDE4 is activated by phosphorylation. In this study, we investigated the expression of PDE4 isoform genes and alternative splicing variants of PDE4D in the rat parotid gland using reverse transcriptase-polymerase chain reaction (RT-PCR). PDE4A, PDE4B, PDE4C and PDE4D of PDE4 subfamily were expressed. PDE4D was found to be the dominant PDE4 isoform. A weak band of PDE4C was detectable. Three alternative splicing variants (PDE4D1, PDE4D2 and PDE4D3) derived from the rat PDE4D gene were expressed in the parotid gland. These data suggested that the intracellular cAMP level is regulated by multiple response mechanisms through the activations of the PDE by phosphorylation and gene expression in the rat parotid gland.
在先前的报告中，我们已经表明，环磷酸腺苷特异性磷酸二酯酶（PDE4）是大鼠腮腺中的主要磷酸二酯酶，并且PDE4通过磷酸化被激活。在本研究中，我们使用逆转录聚合酶链反应（RT-PCR）研究了大鼠腮腺中PDE4亚型基因的表达以及PDE4D的可变剪接变体。PDE4亚家族的PDE4A、PDE4B、PDE4C和PDE4D均有表达。发现PDE4D是主要的PDE4亚型。可检测到一条微弱的PDE4C条带。源自大鼠PDE4D基因的三种可变剪接变体（PDE4D1、PDE4D2和PDE4D3）在腮腺中表达。这些数据表明，大鼠腮腺中细胞内环磷酸腺苷水平通过磷酸化激活磷酸二酯酶和基因表达的多种反应机制来调节。
