Haase Bianca, Humphray Sean J, Lyer Stefan, Renner Marcus, Poustka Annemarie, Mollenhauer Jan, Leeb Tosso
Institute of Genetics, Vetsuisse Faculty, University of Berne, Bremgartenstrasse 109a, 3001 Berne, Switzerland.
Gene. 2006 Jul 19;376(2):184-91. doi: 10.1016/j.gene.2006.03.002. Epub 2006 Mar 20.
The human gene deleted in malignant brain tumors 1 (DMBT1) is considered to play a role in tumorigenesis and pathogen defense. It encodes a protein with multiple scavenger receptor cysteine-rich (SRCR) domains, which are involved in recognition and binding of a broad spectrum of bacterial pathogens. The SRCR domains are encoded by highly homologous repetitive exons, whose number in humans may vary from 8 to 13 due to genetic polymorphism. Here, we characterized the porcine DMBT1 gene on the mRNA and genomic level. We assembled a 4.5 kb porcine DMBT1 cDNA sequence from RT-PCR amplified seminal vesicle RNA. The porcine DMBT1 cDNA contains an open reading frame of 4050 nt. The transcript gives rise to a putative polypeptide of 1349 amino acids with a calculated mass of 147.9 kDa. Compared to human DMBT1, it contains only four N-terminal SRCR domains. Northern blotting revealed transcripts of approximately 4.7 kb in size in the tissues analyzed. Analysis of ESTs suggested the existence of secreted and transmembrane variants. The porcine DMBT1 gene spans about 54 kb on chromosome 14q28-q29. In contrast to the characterized cDNA, the genomic BAC clone only contained 3 exons coding for N-terminal SRCR domains. In different mammalian DMBT1 orthologs large interspecific differences in the number of SRCR exons and utilization of the transmembrane exon exist. Our data suggest that the porcine DMBT1 gene may share with the human DMBT1 gene additional intraspecific variations in the number of SRCR-coding exons.
恶性脑肿瘤缺失基因1（DMBT1）被认为在肿瘤发生和病原体防御中发挥作用。它编码一种具有多个富含半胱氨酸的清道夫受体（SRCR）结构域的蛋白质，这些结构域参与多种细菌病原体的识别和结合。SRCR结构域由高度同源的重复外显子编码，由于基因多态性，其在人类中的数量可能从8个到13个不等。在此，我们在mRNA和基因组水平上对猪DMBT1基因进行了表征。我们从RT-PCR扩增的精囊RNA中组装了一个4.5 kb的猪DMBT1 cDNA序列。猪DMBT1 cDNA包含一个4050 nt的开放阅读框。该转录本产生一个推定的1349个氨基酸的多肽，计算分子量为147.9 kDa。与人类DMBT1相比，它仅包含四个N端SRCR结构域。Northern印迹显示在所分析的组织中存在大小约为4.7 kb的转录本。EST分析表明存在分泌型和跨膜型变体。猪DMBT1基因位于14号染色体q28-q29上，跨度约为54 kb。与已表征的cDNA不同，基因组BAC克隆仅包含3个编码N端SRCR结构域的外显子。在不同的哺乳动物DMBT1直系同源物中，SRCR外显子数量和跨膜外显子的利用存在较大的种间差异。我们的数据表明，猪DMBT1基因可能与人类DMBT1基因在SRCR编码外显子数量上存在其他种内变异。
