The effect of rod domain A148V mutation of neurofilament light chain on filament formation.
Neurofilaments (NFs) are neuronal intermediate filaments composed of light (NF-L), middle (NF-M), and heavy (NF-H) subunits. NF-L self-assembles into a "core" filament with which NF-M or NF-H co-assembles to form the neuronal intermediate filament. Recent reports show that point mutations of the NF-L gene result in Charcot-Marie-Tooth disease (CMT). However, the most recently described rod domain mutant of human NF-L (A148V) has not been characterized in cellular level. We cloned human NF-L and used it to engineer the A148V. In phenotypic analysis using SW13 cells, A148V mutation completely abolished filament formation despite of presence of NF-M. Moreover, A148V mutation reduced the levels of in vitro self-assembly using GST-NF-L (H/R) fusion protein whereas control (A296T) mutant did not affect the filament formation. These results suggest that alanine at position 148 is essentially required for NF-L self-assembly leading to subsequent filament formation in neuronal cells.
Lee
In-Bum
IB
Department of Life Science, College of Natural Science, Daejin University, Pocheon, Korea.
Kim
Sung-Kuk
SK
Chung
Sang-Hee
SH
Kim
Ho
H
Kwon
Taeg Kyu
TK
Min
Do Sik
do S
Chang
Jong-Soo
JS
D000409:Alanine / Q000737:chemistry; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007382:Intermediate Filaments / Q000737:chemistry / Q000378:metabolism; D046912:Multiprotein Complexes; D016297:Mutagenesis, Site-Directed; D016900:Neurofilament Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D016716:PC12 Cells; D010641:Phenotype; D017434:Protein Structure, Tertiary; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D046912:Multiprotein Complexes; D016900:Neurofilament Proteins; D011994:Recombinant Proteins; C044882:neurofilament protein L; C051774:neurofilament protein H; C061195:neurofilament protein M; D000409:Alanine