TY - JOUR
T1 - Molecular cloning and characterization of rat LC3A and LC3B - Two novel markers of autophagosome
AU - Wu, Jiaxue
AU - Dang, Yongjun
AU - Su, Wei
AU - Liu, Chao
AU - Ma, Haijie
AU - Shan, Yuxi
AU - Pei, Yuan
AU - Wan, Bo
AU - Guo, Jinhu
AU - Yu, Long
N1 - Funding Information:
This work was supported by the National 973 Program and 863 High Technology Program of China, as well as the National Natural Science Foundation of China.
PY - 2006/1/6
Y1 - 2006/1/6
N2 - Rat microtubule-associated protein light chain 3 (LC3) is a homologue of yeast Atg8, an essential component of autophagy. Following synthesis, the C-terminus of rat LC3 is cleaved by a cysteine protease-Atg4, to produce LC3-I, which is located in cytosolic fraction. LC3-I can be converted to LC3-II through the processing by Atg7 (E1-like enzyme) and Atg3 (E2-like enzyme). LC3-II is modified by phosphatidylethanolamine on C-terminus and binds tightly to autophagosomal membrane. Here we reported the cloning of two novel variants of rat LC3, named LC3A and LC3B, respectively, and LC3B is an alternative splicing variant of LC3. LC3A, LC3B, and LC3 showed different expression patterns in rat tissues, suggesting a functional divergence among these proteins. When LC3A and LC3B were overexpressed, both exhibited two forms (18 and 16 kDa, representing types of I and II, separately), which might be due to post-translational modification including the characteristic C-terminal cleavage at these two proteins as similar to that found in rat LC3 and yeast Atg8. Subcellular localization demonstrated that both LC3A and LC3B are colocalized with LC3 and associated with the autophagic membranes. Mutation analysis further revealed that the conserved Gly120 residues of LC3A and LC3B are essential for their characteristic C-terminal cleavage and localization to autophagic membranes. Present data suggested that LC3A and LC3B could also be used as two novel autophagosomal markers.
AB - Rat microtubule-associated protein light chain 3 (LC3) is a homologue of yeast Atg8, an essential component of autophagy. Following synthesis, the C-terminus of rat LC3 is cleaved by a cysteine protease-Atg4, to produce LC3-I, which is located in cytosolic fraction. LC3-I can be converted to LC3-II through the processing by Atg7 (E1-like enzyme) and Atg3 (E2-like enzyme). LC3-II is modified by phosphatidylethanolamine on C-terminus and binds tightly to autophagosomal membrane. Here we reported the cloning of two novel variants of rat LC3, named LC3A and LC3B, respectively, and LC3B is an alternative splicing variant of LC3. LC3A, LC3B, and LC3 showed different expression patterns in rat tissues, suggesting a functional divergence among these proteins. When LC3A and LC3B were overexpressed, both exhibited two forms (18 and 16 kDa, representing types of I and II, separately), which might be due to post-translational modification including the characteristic C-terminal cleavage at these two proteins as similar to that found in rat LC3 and yeast Atg8. Subcellular localization demonstrated that both LC3A and LC3B are colocalized with LC3 and associated with the autophagic membranes. Mutation analysis further revealed that the conserved Gly120 residues of LC3A and LC3B are essential for their characteristic C-terminal cleavage and localization to autophagic membranes. Present data suggested that LC3A and LC3B could also be used as two novel autophagosomal markers.
KW - Autophagy
KW - LC3A
KW - LC3B
KW - Post-translational modification
KW - Rat LC3
KW - Subcellular localization
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U2 - 10.1016/j.bbrc.2005.10.211
DO - 10.1016/j.bbrc.2005.10.211
M3 - Article
C2 - 16300744
AN - SCOPUS:28144431882
SN - 0006-291X
VL - 339
SP - 437
EP - 442
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -