O'Leary Nuala A, Gross Paul S
Medical University of South Carolina, Department of Biochemistry and Molecular Biology, Charleston, SC 29425, USA.
Gene. 2006 Apr 12;371(1):75-83. doi: 10.1016/j.gene.2005.11.028. Epub 2006 Feb 20.
Penaeidins are a family of shrimp antimicrobial peptides that have a unique molecular structure consisting of a highly conserved leader peptide followed by an N-terminal proline-rich domain and a C-terminal cysteine-rich domain. Three distinct classes of penaeidins, named PEN2, PEN3, and PEN4, are expressed in the hemocytes of the Pacific white shrimp, Litopenaeus vannamei. Multiple isoforms, generated by substitutions and deletions within the proline and cysteine-rich domains, have been reported at the mRNA level for all three classes of penaeidins suggesting that this is a highly diverse gene family; however, the genetic mechanisms by which sequence variability in the penaeidin gene family is generated are unknown. The present study examines the genomic sources for both class and isoform diversity in the penaeidin family. We show that each penaeidin class is encoded by a unique gene and that isoform diversity is generated by polymorphism within each penaeidin gene locus. Furthermore, the genomic regions upstream of each penaeidin gene were partially characterized and found to drive transcription.
对虾抗菌肽是一类虾类抗菌肽，具有独特的分子结构，由一个高度保守的前导肽、一个富含脯氨酸的N端结构域和一个富含半胱氨酸的C端结构域组成。在凡纳滨对虾的血细胞中表达了三种不同类型的对虾抗菌肽，分别命名为PEN2、PEN3和PEN4。在mRNA水平上，已报道了所有三类对虾抗菌肽在富含脯氨酸和半胱氨酸的结构域内通过替换和缺失产生的多种亚型，这表明这是一个高度多样化的基因家族；然而，对虾抗菌肽基因家族中序列变异性产生的遗传机制尚不清楚。本研究探讨了对虾抗菌肽家族中类型和亚型多样性的基因组来源。我们发现，每一类对虾抗菌肽都由一个独特的基因编码，亚型多样性是由每个对虾抗菌肽基因座内的多态性产生的。此外，对每个对虾抗菌肽基因上游的基因组区域进行了部分表征，发现其可驱动转录。
