Characterization of three types of human alpha s1-casein mRNA transcripts.
Here we report the molecular cloning and sequencing of three types of human alpha s1-casein transcripts and present evidence indicating that exon skipping is responsible for deleted mRNA transcripts. The largest transcript comprised 981 bp encoding a signal peptide of 15 amino acids followed by the mature alpha s1-casein sequence of 170 amino acids. Human alpha s1-casein has been reported to exist naturally as a multimer in complex with kappa-casein in mature human milk, thereby being unique among alpha s1-caseins [Rasmussen, Due and Petersen (1995) Comp. Biochem. Physiol., in the press]. The present demonstration of three cysteines in the mature protein provides a molecular explanation of the interactions in this complex. Tissue-specific expression of human alpha s1-casein was indicated by Northern-blot analysis. In addition, two cryptic exons were localized in the bovine alpha s1-casein gene.
Johnsen
L B
LB
Protein Chemistry Laboratory, University of Aarhus, Denmark.
Rasmussen
L K
LK
Petersen
T E
TE
Berglund
L
L
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002364:Caseins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005091:Exons; D006801:Humans; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012333:RNA, Messenger / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
D002364:Caseins; D018076:DNA, Complementary; D012333:RNA, Messenger