Rabbit surfactant protein C: cDNA cloning and regulation of alternatively spliced surfactant protein C mRNAs.
Surfactant protein C (SP-C), a hydrophobic protein of pulmonary surfactant is essential for surfactant function. Toward elucidating molecular mechanisms that mediate regulation of SP-C gene expression in rabbit lung, we isolated and characterized cDNAs encoding rabbit SP-C and studied the regulation of SP-C gene expression during fetal lung development and by adenosine 3',5'-cyclic monophosphate (cAMP) and dexamethasone in fetal lung tissues in vitro. We found that rabbit SP-C is highly homologous to SP-C of other species and is encoded by two mRNAs that differ by an insertion of 31 nucleotides in the 3' untranslated regions. SP-C mRNAs were classified into two types based on the nucleotide sequence; type I represents RNA without the 31 nucleotide insert and comprises approximately 80-90% of total SP-C mRNA content, whereas type II represents RNA containing the insert and comprises approximately 10-20% of total SP-C mRNA content. SP-C mRNAs were induced in a coordinate manner during fetal lung development and by cAMP and dexamethasone in fetal lung tissues in vitro. Southern hybridization analysis of genomic DNA suggested that SP-C mRNAs are encoded by a single gene. Polymerase [corrected] chain reaction-amplification of genomic DNA with oligonucleotide primers flanking the insertional sequence and sequence analysis of amplified DNA showed that SP-C mRNAs are produced by alternative use of 3' splice sites of intron 5 of SP-C gene.
Boggaram
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Department of Molecular Biology, University of Texas Health Science Center, Tyler 75710.
Margana
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RK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D000242:Cyclic AMP / Q000494:pharmacology; D004247:DNA / Q000235:genetics*; D005314:Embryonic and Fetal Development; D005786:Gene Expression Regulation; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D008168:Lung / Q000196:embryology; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D015345:Oligonucleotide Probes / Q000235:genetics; D016133:Polymerase Chain Reaction; D011510:Proteolipids / Q000235:genetics*; D011663:Pulmonary Surfactants / Q000235:genetics*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D011817:Rabbits; D013045:Species Specificity
D005938:Glucocorticoids; D015345:Oligonucleotide Probes; D011510:Proteolipids; D011663:Pulmonary Surfactants; D012333:RNA, Messenger; D004247:DNA; D000242:Cyclic AMP