Biochemical characterization of Alsin, a Rab5 and Rac1 guanine nucleotide exchange factor

Justin D. Topp, Darren S. Carney, Bruce F. Horazdovsky

Research output: Contribution to journalReview article

13 Scopus citations


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).

Original languageEnglish (US)
Article number22
Pages (from-to)261-276
Number of pages16
JournalMethods in enzymology
StatePublished - Jan 1 2005


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

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