Kotera J, Fujishige K, Akatsuka H, Imai Y, Yanaka N, Omori K
Discovery Research Laboratory, Tanabe Seiyaku Co. Ltd., 2-50, Kawagishi-2-chome, Toda, Saitama, 335-8505, Japan.
J Biol Chem. 1998 Oct 9;273(41):26982-90. doi: 10.1074/jbc.273.41.26982.
After our recent findings that the amino-terminal portion of rat cGMP-binding, cGMP-specific phosphodiesterase (cGB-PDE) differs from those of bovine and human cGB-PDEs, we found two forms of canine cGB-PDE cDNAs (CFPDE5A1 and CFPDE5A2) in canine lung. Each contained a distinct amino-terminal sequence, CFPDE5A1, possessing an amino-terminal portion with sequence similar to those of bovine and human, and CFPDE5A2, having one similar to that of rat. Other portions coding for the cGMP binding domains and the catalytic domain were conserved. Both CFPDE5A1 and CFPDE5A2 transcripts were detected in the cerebellum, hippocampus, retina, lung, heart, spleen, and thoracic artery. CFPDE5A1 transcripts were particularly abundant in the pylorus, whereas CFPDE5A2 transcripts were quite low in this tissue. CFPDE5A1 and CFPDE5A2 expressed in COS-7 cells had cGMP Km values of 2.68 and 1.97 microM, respectively, and both were inhibited by a low concentration of a cGB-PDE inhibitor, Zaprinast. Both CFPDE5A1 and CFPDE5A2 bound cGMP to their allosteric cGMP binding domains, and this cGMP binding was stimulated by 3-isobutyl-1-methylxanthine. Thus, two types of alternative splice variants of canine cGB-PDE have been identified and shown to have similar biological properties in vitro.
在我们最近发现大鼠环磷酸鸟苷（cGMP）结合的、cGMP特异性磷酸二酯酶（cGB-PDE）的氨基末端部分与牛和人的cGB-PDE不同之后，我们在犬肺中发现了两种形式的犬cGB-PDE cDNA（CFPDE5A1和CFPDE5A2）。每种都包含一个独特的氨基末端序列，CFPDE5A1的氨基末端部分的序列与牛和人的相似，而CFPDE5A2的与大鼠的相似。编码cGMP结合域和催化域的其他部分是保守的。在小脑、海马、视网膜、肺、心脏、脾脏和胸主动脉中均检测到CFPDE5A1和CFPDE5A2转录本。CFPDE5A1转录本在幽门中特别丰富，而CFPDE5A2转录本在该组织中相当低。在COS-7细胞中表达的CFPDE5A1和CFPDE5A2的cGMP Km值分别为2.68和1.97 microM，并且两者都被低浓度的cGB-PDE抑制剂扎普司特抑制。CFPDE5A1和CFPDE5A2都将cGMP结合到其变构cGMP结合域，并且这种cGMP结合受到3-异丁基-1-甲基黄嘌呤的刺激。因此，已鉴定出犬cGB-PDE的两种类型的可变剪接变体，并显示它们在体外具有相似的生物学特性。
