The Rat Map1lc3 Family Of Two New Gene Cloning And Function Of A Preliminary Study

Two forms of rat Microtubule-Associated Proteinl Light Chain 3 (Mapllc3) exist and serve as a subunit of the microtubule-associated protein 1 and an essential constituent of autophagosome membranes, respectively. In vivo, the two functional forms of rat Mapllc3 with apparent mobilities of 18 and 16KDa, termed Lc3-I and Lc3-II, separately, were produced by a series of post-translational modifications including a characteristic C-terminal cleavage after the conserved Glyl20 residue and this cleavage is essential for the membrane association of the 16KDa rat Map1lc3 protein., we cloned two novel isoforms of rat Map1LC3 by bioinformatics and named MapILCSA and Map1LC3B, respectively. The tissue distribution of transcription of two genes is different. In addition, They were transfected into human HEK293T cells and analyzed by immunoblotting, suggesting that two forms of posttranslational modification existed in rat MaplLC3A/B, which is similar to that found in rat Mapllc3 and yeast Apg8p. Mutational and deletion analysis indicated that the conserved Gly residue is crucial for the post-translational modifications of MaplLC3A and B. Moreover, the amounts of larger MAP1LC3A and B proteins were more abundant than that of smaller MAP1C3A and B proteins, respectively. Subcellular localization by immunofluorescence revealed that two rat isoforms are associated with the autophagic pathway. These results are help to discover the mechanisms and functions of autophagy in vivo.