Tellam R L, Vuocolo T, Eisemann C, Briscoe S, Riding G, Elvin C, Pearson R
CSIRO Molecular Animal Genetics Center, CSIRO Livestock Industries, 3rd Floor Gehrmann Laboratories, The University of Queensland, St Lucia, 4067, Queensland, Australia.
Insect Biochem Mol Biol. 2003 Feb;33(2):239-52. doi: 10.1016/s0965-1748(02)00208-4.
A mucin-like glycoprotein, peritrophin-55 was isolated and purified from the peritrophic matrix of Lucilia cuprina larvae. When injected into sheep, peritrophin-55 induced an immune response that inhibited larval growth by 51-66% when larvae subsequently fed on sera from the vaccinated sheep. The protein may have potential use as an immunogen probably accompanying other antigens to protect sheep from the cutaneous myiasis caused by these larvae. Peritrophin-55 was uniformly distributed throughout the peritrophic matrix where it probably lubricates the surface of the peritrophic matrix and protects the midgut from invasion by bacteria. The protein consists of an 8-cysteine amino-terminal domain (peritrophin-B domain) and a carboxy-terminal proline and threonine-rich domain with high probability for extensive O-linked glycosylation. The gene consists of two exons separated by a small intron. Peritrophin-55 mRNA was only detected in the larval cardia and midgut and to a minor extent in the hindgut. Sequence upstream of the transcriptional start site contained a putative promoter region, sequence similar to an ecdysone response element, sequence related to the Drosophila transposon S element and a tetranucleotide repeat region. A putative Drosophila melanogaster ortholog or paralog of peritrophin-55 (CG7714) was located within a 3458 bp intron of the Cha gene (choline-O-acetyltransferase), but on the opposite strand. Comparison of the putative promoter regions of the peritrophin-55 and CG7714 genes revealed little similarity except for a small semi-conserved sequence that is suggestive of a common transcription factor-binding site possibly contributing to the highly restricted developmental and tissue-specific expression patterns of these genes.
一种类粘蛋白糖蛋白——围食膜蛋白-55，是从铜绿蝇幼虫的围食膜中分离纯化得到的。将围食膜蛋白-55注射到绵羊体内后，当幼虫随后取食来自接种疫苗绵羊的血清时，它会引发一种免疫反应，这种反应会使幼虫生长受到51% - 66%的抑制。该蛋白可能具有作为免疫原的潜在用途，可能与其他抗原一起保护绵羊免受这些幼虫引起的皮肤蝇蛆病侵害。围食膜蛋白-55均匀分布于整个围食膜基质中，它可能在围食膜基质表面起到润滑作用，并保护中肠免受细菌侵袭。该蛋白由一个含8个半胱氨酸的氨基末端结构域（围食膜蛋白-B结构域）和一个羧基末端富含脯氨酸和苏氨酸的结构域组成，具有高度广泛的O-连接糖基化可能性。该基因由两个外显子组成，中间被一个小内含子隔开。围食膜蛋白-55 mRNA仅在幼虫贲门和中肠中检测到，在后肠中也有少量表达。转录起始位点上游的序列包含一个推定的启动子区域、与蜕皮激素反应元件相似的序列、与果蝇转座子S元件相关的序列以及一个四核苷酸重复区域。围食膜蛋白-55的一个推定的黑腹果蝇直系同源物或旁系同源物（CG7714）位于Cha基因（胆碱-O-乙酰转移酶）的一个3458 bp内含子内，但位于相反链上。围食膜蛋白-55和CG7714基因推定启动子区域的比较显示，除了一个小的半保守序列外，几乎没有相似性，该半保守序列提示可能存在一个共同的转录因子结合位点，这可能导致这些基因具有高度受限的发育和组织特异性表达模式。
