ALS2/alsin deficiency in neurons leads to mild defects in macropinocytosis and axonal growth.
Loss of function mutations in the ALS2 gene account for a number of juvenile/infantile recessive motor neuron diseases, indicating that its gene product, ALS2/alsin, plays a crucial role in maintenance and survival for a subset of neurons. ALS2 acts as a guanine nucleotide exchange factor (GEF) for the small GTPase Rab5 and is implicated in endosome dynamics in cells. However, the role of ALS2 in neurons remains unclear. To elucidate the neuronal ALS2 functions, we investigate cellular phenotypes of ALS2-deficient primary cultured neurons derived from Als2-knockout (KO) mice. Here, we show that ALS2 deficiency results not only in the delay of axon outgrowth in hippocampal neurons, but also in a decreased level of the fluid phase horseradish peroxidase (HRP) uptake, which represents the activity for macropinocytic endocytosis, in cortical neurons. Thus, ALS2 may act as a modulator in neuronal differentiation and/or development through regulation of membrane dynamics.
Otomo
Asako
A
Neurodegenerative Diseases Research Centre, Graduate School of Medicine, Tokai University, Isehara, Kanagawa 259-1193, Japan.
Kunita
Ryota
R
Suzuki-Utsunomiya
Kyoko
K
Mizumura
Hikaru
H
Onoe
Kyuichiro
K
Osuga
Hitoshi
H
Hadano
Shinji
S
Ikeda
Joh-E
JE
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000502:physiology*; D002454:Cell Differentiation; D002478:Cells, Cultured; D020662:Guanine Nucleotide Exchange Factors / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009474:Neurons / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D010873:Pinocytosis / Q000235:genetics; D011554:Pseudopodia / Q000737:chemistry / Q000378:metabolism
C512358:Als2 protein, mouse; D020662:Guanine Nucleotide Exchange Factors