Hammarback J A, Obar R A, Hughes S M, Vallee R B
Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545.
Neuron. 1991 Jul;7(1):129-39. doi: 10.1016/0896-6273(91)90081-a.
Microtubule-associated protein 1B (MAP1B), an abundant developmentally regulated neuronal protein, is a stoichiometric complex of a heavy chain and two light chains (light chain 1 and light chain 3). We find that light chain 1 is encoded within the 3' end of a previously reported MAP1B heavy chain cDNA. Amino acid sequencing, epitope mapping, Northern blotting, and Southern blotting indicate that the light chain and heavy chain are encoded by the same mRNA within the same open reading frame. In addition, amino acid sequencing of a 120 kd microtubule-binding and light chain-binding fragment of the heavy chain reveals that light chain 1 binds near the heavy chain N-terminus. Together these data indicate that the heavy chain and light chain 1 are produced by proteolytic processing of a MAP1B polyprotein and form a complex microtubule-binding domain.
微管相关蛋白1B（MAP1B）是一种在发育过程中受调控的丰富神经元蛋白，是由一条重链和两条轻链（轻链1和轻链3）组成的化学计量复合物。我们发现轻链1编码于先前报道的MAP1B重链cDNA的3'末端。氨基酸测序、表位作图、Northern印迹和Southern印迹表明，轻链和重链由同一开放阅读框内的同一mRNA编码。此外，对重链的一个120kd微管结合和轻链结合片段进行氨基酸测序发现，轻链1结合在重链N末端附近。这些数据共同表明，重链和轻链1是由MAP1B多蛋白经蛋白水解加工产生的，并形成一个复杂的微管结合结构域。
