title: The bicistronic nature of lens alpha-crystallin 14S mRNA.
abstract: The A2 and B2 polypeptide chains of calf lens alpha-crystallin are synthesized on a 14S, 1500-nucleotide mRNA and a 10S, 735-nucleotide mRNA, respectively. The 10S mRNA is theoretically compatible with the size of the B2 chain, but the 14S mRNA contains approximately twice the required number of nucleotides necessary for A2 chain synthesis. This fact raises the question of the function of the additional nucleotide sequence in the 14S mRNA. The following observations on 14S mRNA suggest that it may contain an additional cistron. (i) Under a number of denaturing conditions, 14S mRNA continues to retain its initial size characteristics. (ii) In addition to synthesis of the A2 chain, 14S mRNA directs the synthesis of another polypeptide with the same electrophoretic mobility as that of the B2 chain. (iii) Molecular hybridization of the 14S mRNA with the cDNA produced from the 10S mRNA suggests that 2 mol of the cDNA bind to 1 mol of the 14S mRNA. (iv) Examination of the nucleotide sequences of the 10S and 14S mRNAs by two-dimensional maps of RNase A and T1 digests indicates marked similarity. The overall data suggest that the additional cistronic component may carry coding information for an alpha-crystallin polypeptide or a closely related polypeptide species.
mesh_terms: D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003459:Crystallins / Q000235:genetics*; D005796:Genes; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000032:analysis; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*
chemical_list: D003459:Crystallins; D009841:Oligonucleotides; D012333:RNA, Messenger
references.citation: Proc Natl Acad Sci U S A. 1977 Jan;74(1):178-82
references.pmid: 264673
references.citation: J Mol Biol. 1976 Oct 5;106(4):1067-75
references.pmid: 824454
references.citation: J Mol Biol. 1976 Sep 15;106(2):403-20
references.pmid: 978727
references.citation: J Mol Biol. 1976 Sep 5;106(1):109-31
references.pmid: 61277
references.citation: Biochemistry. 1977 Feb 8;16(3):499-505
references.pmid: 836798
references.citation: Eur J Biochem. 1976 Aug 16;67(2):563-7
references.pmid: 964258
references.citation: Proc Natl Acad Sci U S A. 1974 Jun;71(6):2300-4
references.pmid: 4135409
references.citation: Q Rev Biol. 1973 Dec;48(4):565-613
references.pmid: 4592421
references.citation: Biochem Biophys Res Commun. 1973 Jun 8;52(3):767-73
references.pmid: 4122884
references.citation: Biochemistry. 1974 Jul 16;13(15):3159-63
references.pmid: 4135218
references.citation: Biochim Biophys Acta. 1976 Jan 5;418(1):39-51
references.pmid: 54193
references.citation: Nature. 1976 Sep 16;263(5574):211-4
references.pmid: 822353
references.citation: Science. 1973 Sep 28;181(4106):1215-21
references.pmid: 4542191
references.citation: Cold Spring Harb Symp Quant Biol. 1974;38:525-35
references.pmid: 4524773
references.citation: Proc Natl Acad Sci U S A. 1974 Nov;71(11):4327-31
references.pmid: 4530986
references.citation: Biochem Biophys Res Commun. 1974 Aug 5;59(3):1157-64
references.pmid: 4472373
references.citation: Nucleic Acids Res. 1974 Feb;1(2):245-55
references.pmid: 4472020
references.citation: Eur J Biochem. 1974 Nov 1;49(1):157-68
references.pmid: 4477528
references.citation: Biochem Biophys Res Commun. 1974 Mar 15;57(1):134-41
references.pmid: 4828184
references.citation: J Mol Biol. 1974 Jan 5;82(1):15-25
references.pmid: 4818481
references.citation: Exp Eye Res. 1974 Feb;18(2):189-99
references.pmid: 4825729
references.citation: Eur J Biochem. 1969 Dec;11(2):395-9
references.pmid: 4902612