CHARACTERIZATION OF MESSENGER-RNA TRANSCRIPTS AND ORGANIZATION OF HUMAN SP-A1 AND SP-A2 GENES
CHARACTERIZATION OF MESSENGER-RNA TRANSCRIPTS AND ORGANIZATION OF HUMAN SP-A1 AND SP-A2 GENES
复制标题
DOI：
10.1152/ajplung.1994.266.4.l354
复制
发表时间：
1994-04-01
影响因子：
--
通讯作者：
MENDELSON, CR
中科院分区：
文献类型：
--
作者：
MCCORMICK, SM;BOGGARAM, V;MENDELSON, CR
在本研究中，我们的特点是人类表面活性蛋白（SP）A1和SP-A2基因的mRNA转录和内含子-外显子组织。通过使用外显子II的寡核苷酸引物（如SP-A1基因中所述）对从人胎肺外植体中分离的mRNA进行引物延伸分析，观察到至少9个引物延伸的转录物。采用cDNA末端快速扩增法扩增引物延伸转录本进行序列分析。对47个全长引物延伸的cDNA进行序列分析，并与编码SP-A1和SP-A2的基因的序列进行比较，揭示了SP-A2基因的4种不同类型的转录本和SP-A1基因的5种不同类型的转录本。SP-A2和SP-A1 mRNA转录本之间的主要差异在于SP-A2转录本总是由六个外显子内包含的序列组成; SP-A2中的额外外显子（VI的外显子II）编码额外的5 '非翻译序列，并且位于SP-A1的外显子I和II之间。相比之下，SP-A1基因的大部分转录本由五个外显子内包含的序列组成。在SP-A1和SP-A2基因的情况下，一小部分mRNA转录物含有存在于交替外显子中的序列。此外，大多数SP-A1 mRNA转录物起始于SP-A2转录起始位点下游5 bp处。在我们的配套文件[麦考密克和门德尔松。Am. J. Physiol.266（Lung Cell.摩尔生理学10）：L367-L374，1994]，我们报道了SP-A1和SP-A2基因在发育过程中以及在培养的人胎肺中受到腺苷3 '，5'-环一磷酸和糖皮质激素的不同调节。
In the present study, we have characterized the mRNA transcripts and intron-exon organization of the human surfactant protein (SP)A1 and SP-A2 genes. By primer extension analysis of mRNA isolated from human fetal lung explants using an oligonucleotide primer to exon II (as delineated in the SP-A1 gene), a minimum of nine primer extended transcripts was observed. Rapid amplification of cDNA ends was used to amplify the primer extended transcripts for sequence analysis. Sequence analysis of 47 full-length primer extended cDNAs and comparison with the sequences of the genes encoding SP-A1 and SP-A2 revealed four different classes of transcripts of the SP-A2 gene and five different classes of transcripts of the gene encoding SP-A1. A major difference between SP-A2 and SP-A1 mRNA transcripts is that SP-A2 transcripts are always comprised of sequences contained within six exons; the extra exon in SP-A2 (exon II of VI) encodes additional 5'-untranslated sequence and is located between exons I and II of SP-A1. By contrast, the majority of transcripts of the SP-A1 gene are comprised of sequences contained within five exons. In the cases of both SP-A1 and SP-A2 genes, a small proportion of the mRNA transcripts contain sequences present in alternate exons. In addition, the majority of the SP-A1 mRNA transcripts are initiated 5 bp downstream of the transcription initiation site of SP-A2. In our companion paper [McCormick and Mendelson. Am. J. Physiol. 266 (Lung Cell. Mol. Physiol. 10): L367-L374, 1994], we report that the SP-A1 and SP-A2 genes are differentially regulated during development and by adenosine 3',5'-cyclic monophosphate and glucocorticoids in human fetal lung in culture.