MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them a...MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them are highly conserved. With the miRNA roles identified in nearly all aspects of biological processes, evidence is mounting that miRNAs could represent a new layer of regulatory network, and their regulatory effect might be much more pervasive than previously suspected. Here we focus on the posttranscriptional level gene regulation of miRNAs in animals and review how the miRNAs act to sustain and shape up the expression profiles of specific cell types; how the miRNAs integrate into the existing gene regulatory networks; and how the miRNAs influence the evolution of 3＇UTR of mammalian mRNAs.展开更多
The cDNA insert of the plasmid p14-6[1] is found to be the 3’-untranslatcd region (3’-UTR) of the transcription factor for human interleukin-6, NF-IL6. This 3’ -DTK is actively transcribed in the revertant cell lin...The cDNA insert of the plasmid p14-6[1] is found to be the 3’-untranslatcd region (3’-UTR) of the transcription factor for human interleukin-6, NF-IL6. This 3’ -DTK is actively transcribed in the revertant cell line RR, which contains the p14-6 plasmid integrated into its genomic DNA. Simultaneously a protein specifically bound to this 3’-UTR is expressed in significantly larger amounts. Its overexpression is apparently related to the reversion of the malignant cellular phenotype. The properties of this protein, named BNF, and possible reasons for its overexpression are discussed, and hypothesis on the mechanism of reversion of the RR cells is proposed.展开更多
Leptinotarsa decemlineata adults exhibit a season-dependent activity. In spring, post-diapause beetles often fly a long distance from overwintering sites to potato fields. In summer and autumn, the flight ability is s...Leptinotarsa decemlineata adults exhibit a season-dependent activity. In spring, post-diapause beetles often fly a long distance from overwintering sites to potato fields. In summer and autumn, the flight ability is sharply reduced. Proline is the main energy substrate ofL. decemlineata during flight and proline dehydrogenase （ProDH） catalyzes the first step in proline catabolism. Here we identified a putative LdProDHgene; it had three cDNA isoforms which shared the same 5＇UTR and coding region, but differed in the lengths of 3＇UTRs （515, 1 092 and 1 242 bp for isoforms-1, -2 and -3, respectively）. LdProDH encoded a 616 amino acid protein that showed high sequence similarity to ProDH-like proteins from other insect species. LdProDHwas expressed in the third and fourth instars larvae and adults, but not in pupae. Dietary ingestion of bacterially expressed LdProDH- dsRNA by adults significantly decreased its messenger RNA （mRNA） level, and caused an elevation of free proline content in the hemolymph. Further observation revealed that three canonical polyadenylation signals （AATAAA） were tandemly located in the 3＇UTR of isoform-3. The first, second and third polyadenylation sites gave rise to isoforms-1, -2 and -3, respectively. Analysis of the genomic DNA uncovered that the three isoforms resulted from alternative polyadenylation. The mRNA level of isoform-1, which expressed at low levels in pre-diapause adults, became abundant in post-diapause beetles. It is indicated that the LdProDH expression is fine-tuned through 3＇UTR to control proline catabolism for the season-dependent activity ofL. decemlineata adults.展开更多
基金supported by the National Basic Research Program of China (973 Program) (No. 2006CB701506 and 2007CB815705)the Chinese Academy of Sciences (No. KSCX1-YW-R-34)+1 种基金the National Natural Science Foundation of China (No. 30525028, 30630013 and 30871343)the Natural Science Foundation of Yunnan Province of China.
文摘MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them are highly conserved. With the miRNA roles identified in nearly all aspects of biological processes, evidence is mounting that miRNAs could represent a new layer of regulatory network, and their regulatory effect might be much more pervasive than previously suspected. Here we focus on the posttranscriptional level gene regulation of miRNAs in animals and review how the miRNAs act to sustain and shape up the expression profiles of specific cell types; how the miRNAs integrate into the existing gene regulatory networks; and how the miRNAs influence the evolution of 3＇UTR of mammalian mRNAs.
基金Project supported by the 863 Program,National Science and Technology Commission, China.
文摘The cDNA insert of the plasmid p14-6[1] is found to be the 3’-untranslatcd region (3’-UTR) of the transcription factor for human interleukin-6, NF-IL6. This 3’ -DTK is actively transcribed in the revertant cell line RR, which contains the p14-6 plasmid integrated into its genomic DNA. Simultaneously a protein specifically bound to this 3’-UTR is expressed in significantly larger amounts. Its overexpression is apparently related to the reversion of the malignant cellular phenotype. The properties of this protein, named BNF, and possible reasons for its overexpression are discussed, and hypothesis on the mechanism of reversion of the RR cells is proposed.
文摘Leptinotarsa decemlineata adults exhibit a season-dependent activity. In spring, post-diapause beetles often fly a long distance from overwintering sites to potato fields. In summer and autumn, the flight ability is sharply reduced. Proline is the main energy substrate ofL. decemlineata during flight and proline dehydrogenase （ProDH） catalyzes the first step in proline catabolism. Here we identified a putative LdProDHgene; it had three cDNA isoforms which shared the same 5＇UTR and coding region, but differed in the lengths of 3＇UTRs （515, 1 092 and 1 242 bp for isoforms-1, -2 and -3, respectively）. LdProDH encoded a 616 amino acid protein that showed high sequence similarity to ProDH-like proteins from other insect species. LdProDHwas expressed in the third and fourth instars larvae and adults, but not in pupae. Dietary ingestion of bacterially expressed LdProDH- dsRNA by adults significantly decreased its messenger RNA （mRNA） level, and caused an elevation of free proline content in the hemolymph. Further observation revealed that three canonical polyadenylation signals （AATAAA） were tandemly located in the 3＇UTR of isoform-3. The first, second and third polyadenylation sites gave rise to isoforms-1, -2 and -3, respectively. Analysis of the genomic DNA uncovered that the three isoforms resulted from alternative polyadenylation. The mRNA level of isoform-1, which expressed at low levels in pre-diapause adults, became abundant in post-diapause beetles. It is indicated that the LdProDH expression is fine-tuned through 3＇UTR to control proline catabolism for the season-dependent activity ofL. decemlineata adults.
