Molecular characterization of light chain 3. A microtubule binding subunit of MAP1A and MAP1B.
Molecular characterization of light chain 3. A microtubule binding subunit of MAP1A and MAP1B.
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DOI：
10.1016/s0021-9258(19)78150-2
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发表时间：
1994-04
期刊：
影响因子：
--
通讯作者：
S. S. Mann-S.;J. Hammarback
中科院分区：
文献类型：
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作者：
S. S. Mann-S.;J. Hammarback
轻链3（LC 3）是神经元微管相关蛋白（MAP）MAP 1A和MAP 1B的亚基。最近的发现表明，MAP 1A和MAP 1B的cDNA编码分别含有MAP 1A或MAP 1B重链和LC 2或LC 1亚基的多聚蛋白。我们已经测序了编码大鼠LC 3的cDNA，并且其序列在MAP 1A/LC 2或MAP 1B/LC 1多蛋白cDNA中未发现。LC 3的氨基酸序列在大鼠和小鼠之间高度保守。大鼠LC 3是一种16.4 kDa的蛋白质，预测pI为9.2。它由1.7-脱氢酶mRNA编码。我们的抗LC 3抗血清显示LC 3仅在神经元中丰富，并且脑中的大多数LC 3与微管共纯化。纯化的重组大鼠LC 3保留了与在脑MAP存在下组装的微管以及与由纯化的微管蛋白组装的微管缔合的能力。我们认为LC 3主要作为MAP 1A和MAP 1B亚基发挥功能，其表达可以调节MAP 1A和MAP 1B的微管结合活性。
Light chain 3 (LC3) is a subunit of the neuronal microtubule-associated proteins (MAPs), MAP1A and MAP1B. Recent findings show that the cDNAs for MAP1A and MAP1B encode polyproteins that contain the MAP1A or MAP1B heavy chain and a LC2 or LC1 subunit, respectively. We have sequenced a cDNA encoding rat LC3, and its sequence is not found in the MAP1A/LC2 or MAP1B/LC1 polyprotein cDNAs. The deduced amino acid sequence of LC3 is highly conserved between rat and mouse. Rat LC3 is a 16.4-kDa protein with a predicted pI of 9.2. It is encoded on a 1.7-kilobase mRNA. Our anti-LC3 antiserum shows that LC3 is abundant only in neurons and that the majority of LC3 in brain co-purifies with microtubules. Purified recombinant rat LC3 retains the ability to associate with microtubules assembled in the presence of brain MAPs and with microtubules assembled from purified tubulin. We propose that LC3 functions primarily as a MAP1A and MAP1B subunit and that its expression could regulate the microtubule binding activity of MAP1A and MAP1B.