Cohen syndrome-associated protein COH1 physically and functionally interacts with the small GTPase RAB6 at the Golgi complex and directs neurite outgrowth

Wenke Seifert, Jirko Kühnisch, Tanja Maritzen, Stefanie Lommatzsch, Hans Christian Hennies, Sebastian Bachmann, Denise Horn, Volker Haucke

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25 Citations (Scopus)


Postnatal microcephaly, intellectual disability, and progressive retinal dystrophy are major features of autosomal recessive Cohen syndrome, which is caused by mutations in the gene COH1 (VPS13B). We have recently identified COH1 as a Golgienriched scaffold protein that contributes to the structural maintenance and function of the Golgi complex. Here, we show that association of COH1 with the Golgi complex depends on the small GTPase RAB6. RNAi-mediated knockdown of RAB6A/A' prevents the localization of COH1 to the Golgi complex. Expression of the constitutively inactive RAB6 T27N mutant led to an increased solubilization of COH1 from lipid membrane preparations. Co-IP experiments confirmed the physical interaction of COH1 with RAB6 that preferentially occurred with the constitutively active RAB6 Q72L mutants. Depletion of COH1 in primary neurons negatively interfered with neurite outgrowth, indicating a causal link between the integrity of the Golgi complex and axonal outgrowth. We conclude that COH1 is a RAB6 effector protein and that reduced brain size in Cohen syndrome patients likely results from impaired COH1 function at the Golgi complex, causing decreased neuritogenesis.

Original languageEnglish
Pages (from-to)3349-3358
Number of pages10
JournalJournal of Biological Chemistry
Issue number6
Early online date9 Dec 2014
Publication statusPublished - 6 Feb 2015
Externally publishedYes


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