Biochemical characterization of Alsin, a Rab5 and Rac1 guanine nucleotide exchange factor.
Alsin is the gene product mutated in three juvenile-onset neurodegenerative disorders including amyotrophic lateral sclerosis 2 (ALS2). Sequence motif searches within Alsin predict the presence of Vps9, DH, and PH domains, implying that Alsin may function as a guanine nucleotide exchange factor (GEF) for Rab5 and a member of the Rho GTPase family. Procedures are presented in this chapter for the expression, purification, and biochemical characterization of the individual GEF domains of Alsin. A fractionation method is also described for the determination of Alsin's subcellular distribution. The presence of both Rac1 and Rab5 GEF activities makes Alsin a unique dual exchange factor that may couple endocytosis (via Rab5 activation) to cytoskeletal modulation (via Rac1 activation).
Topp
Justin D
JD
Carney
Darren S
DS
Horazdovsky
Bruce F
BF
D020558:GTP Phosphohydrolases / Q000378:metabolism; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D020798:Two-Hybrid System Techniques
C438187:ALS2 protein, human; D020662:Guanine Nucleotide Exchange Factors; D011994:Recombinant Proteins; D020558:GTP Phosphohydrolases