5' untranslated leader sequences of eukaryotic mRNAs encoding heat shock induced proteins.
5' untranslated leaders (5' UTLs) are suggested to play a crucial role in the selective translation of their eukaryotic mRNAs encoding heat shock proteins (HSP) during heat stress conditions. However, the structural features of the HSP mRNAs which cause this effect are mostly unknown. We have compiled the 5' UTLs from about 140 eukaryotic HSP mRNAs including vertebrates, invertebrates, higher and lower plants. A detailed analysis of these sequences according to length, A+T content, context of functional ATGs and presence of upstream non-functional ATGs was made. We observed that all these features were similar to the earlier studies in the literature based on data from HSP as well as non-HSP mRNAs. These observations were reconfirmed by intra-specific comparison of 5' UTLs from HSP and non-HSP genes. Similar to the translation element involved in the selective translation of mRNAs in polioviruses, a search for a short sequence motif complementary to highly conserved 18S rRNA was performed using a HSP mRNA database. The majority of the HSP mRNA sequences (77%) contained one or more small sequence motifs suggesting that they may function as internal ribosome entry sites for selective initiation of translation during heat stress.
Joshi
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CP
Department of Plant and Soil Sciences, Texas Tech University, Lubbock 79409-2122.
Nguyen
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HT
D000828:Animal Population Groups / Q000235:genetics; D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D003062:Codon; D004275:DNA, Ribosomal / Q000235:genetics; D005057:Eukaryotic Cells / Q000378:metabolism; D005658:Fungi / Q000235:genetics; D006360:Heat-Shock Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010944:Plants / Q000235:genetics; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics*; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid
D003062:Codon; D004275:DNA, Ribosomal; D006360:Heat-Shock Proteins; D012333:RNA, Messenger; D012337:RNA, Ribosomal, 18S