Lin-4

lin-4 microRNA precursor
	预测的lin-4二级结构和保守序列
识别符
代号	lin-4
Rfam	RF00052
miRBase	MI0000002
miRBase	MIPF0000303
	其他数据
RNA类型	Gene; miRNA
域	Eukaryota

lin-4是最早发现的microRNA，1993年由维克托·安布罗斯等人在模式生物秀麗隱桿線蟲的基因组中发现。 ^[1]^[2] 这是第一个被发现的miRNA，是一类参与基因调控的非編碼核糖核酸。^[3] miRNA转录形成70碱基的前体后由Dicer酶切割形成21碱基的产物^[4]。发夹结构前体的范围一般不为人所知，是根据发夹结构预测来估计的。这些产物被认为通过与mRNA完全或部分互补而发挥调节作用。已发现lin-4基因位于一个单独宿主基因的 4.11kb 内含子内（参见[1]）。

转录

lin-4由自主miRNA启动子转录，并受发育调控，lin-4 miRNA积累发生在胚胎后发育的L2阶段。此外，在lin-4成熟形式出现时，内源性lin-4 初级转录本也会上调。^[5] lin-4位于秀丽隐杆线虫的II号染色体上，与lin-14（英语：lin-14） mRNA 的3' 非轉譯區 (UTR)中的序列互补，该互补转录本含有7个结合位点以及9个核苷酸核心元素CUCAGGGAA。lin-4:lin-14双链体呈现出一种不寻常的扭结结构，这是由于碱基对不匹配导致凹槽尺寸和碱基堆积发生变化所致。^[5] 该lin-4:lin-14对与秀丽隐杆线虫中的IGF-1通路有关，与其发育的改变有关。^[6]

發育影響

lin-4決定線蟲幼蟲發育事件的開始。

参考文献

^ Lee RC, Feinbaum RL, Ambros V. The C. elegans heterochronic gene lin-4 encodes small RNAs with antisense complementarity to lin-14.. Cell. 1993, 75 (5): 843–854. PMID 8252621. doi:10.1016/0092-8674(93)90529-Y .
^ Rougvie, AE. Control of developmental timing in animals. Nat Rev Genet. 2001, 2 (9): 690–701. PMID 11533718. doi:10.1038/35088566.
^ Ambros, V. microRNAs: tiny regulators with great potential. Cell. 2001, 107 (7): 823–826. PMID 11779458. doi:10.1016/S0092-8674(01)00616-X .
^ Rougvie, AE. Control of developmental timing in animals. Nat Rev Genet. 2001, 2 (9): 690–701. PMID 11533718. doi:10.1038/35088566.
^ ^5.0 ^5.1 Balasubramanian C, Ojha RP, Maiti S, Desideri A. Sampling the structure of the noncanonical lin-4:lin-14 microRNA:mRNA complex by molecular dynamics simulations.. J Phys Chem B. 2010, 114 (49): 16443–9. PMID 21090710. doi:10.1021/jp104193r.
^ Boehm M, Slack F. A developmental timing microRNA and its target regulate life span in C. elegans.. Science. 2005, 310 (5756): 1954–7. PMID 16373574. doi:10.1126/science.1115596.

外部链接

[pmid8252621-1] Lee RC, Feinbaum RL, Ambros V. The C. elegans heterochronic gene lin-4 encodes small RNAs with antisense complementarity to lin-14.. Cell. 1993, 75 (5): 843–854. PMID 8252621. doi:10.1016/0092-8674(93)90529-Y .

[2] Rougvie, AE. Control of developmental timing in animals. Nat Rev Genet. 2001, 2 (9): 690–701. PMID 11533718. doi:10.1038/35088566.

[3] Ambros, V. microRNAs: tiny regulators with great potential. Cell. 2001, 107 (7): 823–826. PMID 11779458. doi:10.1016/S0092-8674(01)00616-X .

[4] Rougvie, AE. Control of developmental timing in animals. Nat Rev Genet. 2001, 2 (9): 690–701. PMID 11533718. doi:10.1038/35088566.

[pmid21090710-5] 5.0 ^5.1 Balasubramanian C, Ojha RP, Maiti S, Desideri A. Sampling the structure of the noncanonical lin-4:lin-14 microRNA:mRNA complex by molecular dynamics simulations.. J Phys Chem B. 2010, 114 (49): 16443–9. PMID 21090710. doi:10.1021/jp104193r.

[pmid16373574-6] Boehm M, Slack F. A developmental timing microRNA and its target regulate life span in C. elegans.. Science. 2005, 310 (5756): 1954–7. PMID 16373574. doi:10.1126/science.1115596.

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