长寿保障基因LAG1是从酵母中克隆的与酵母寿命相关的基因,随酵母生命衰老而表达发生变化. 对大鼠中同源基因LASS1进行克隆、测序和序列分析,发现其mRNA序列不同于GenBank中的预测序列,开放阅读框包含1 053碱基对,编码蛋白由350个氨基酸组成,内含Lag1蛋白家族保守的Lag1p motif和TLC结构域. 从新生、1月龄、6月龄、12月龄和24月龄大鼠脑顶叶皮质提取总RNA,用半定量RT-PCR及RNA印迹方法对LASS1在大鼠脑皮质中的表达随年龄变化情况进行分析. 结果表明,出生后LASS1表达量随年龄增加而增高,至6月龄达高峰,然后随年龄增加而逐渐下降,至24月老龄鼠达最低. 衰老相关β半乳糖苷酶(SA-β-gal)对鼠脑皮层染色发现,神经元阳性染色随年龄增长明显增加. 大鼠LASS1基因表达在正常衰老过程中发生变化,为进一步研究该基因的作用奠定了基础.
LAG1 was identified as a gene that is differentially expressed during the yeast replicative life span and was shown to play a role in determining yeast longevity. The cDNA of rat LASS1, the mammalian homolog of yeast LAG1, was cloned from rat cerebral cortex and sequenced, which is different to the predicted sequence in the GenBank. Sequence analysis revealed that this cDNA clone contains an open reading frame of 1 053 bp. The deduced amino acid sequence has 350 residues and shares a predicted Lag1p motif and a TLC domain conserved in Lag1 proteins. Total RNAs were isolated from rat cerebral cortices at varying ages: newborn, one month, six months, twelve months, and twenty-four months. Semi-quantitative RT-PCR and Northern blot analysis were performed to analyze the LASS1 expression level in rat cerebral cortex tissues at varying ages. Senescence-associated β-galactosidase (SA-β-gal) activity was firstly used as a biomarker for assessing senescence in rat neurons. The results showed that LASS1 expression was upregulated from newborn to adult rats (1~6 month) and declined in aged cortex. SA-β-gal staining positive neurons significantly increased in the aged cerebral cortex. The age-related expression alternation of LASS1 in rat cerebral cortex provides an important clue in exploring the role of LASS1 in mammalian neuron aging.
王宝恒,傅玉才,史桂芝,许铭炎,耿义群,徐小虎,许锦阶.LASS1基因克隆及其在大鼠脑皮层的表达与神经元衰老的相关性初步研究[J].生物化学与生物物理进展,2006,33(8):760-768
复制生物化学与生物物理进展 ® 2024 版权所有 ICP:京ICP备05023138号-1 京公网安备 11010502031771号