Cytoplasmic dynein-2 is the motor for retrograde intraflagellar transport and mutations in dynein-2 are known to cause skeletal ciliopathies. Here we define for the first time the composition of the human cytoplasmic dynein-2 complex. We show that the ciliopathy genes WDR34 and WDR60 are bona fide dynein-2 intermediate chains and are both required for dynein-2 function. In addition, we identify TCTEX1D2 as a unique dynein-2 light chain that is itself required for cilia function. We define several subunits common to both dynein-1 and dynein-2 including TCTEX-1 and -3, Roadblock-1 and -3, and LC8-1 and -2 light chains. We also find that NudCD3 associates with dynein-2 as it does with dynein-1. In contrast, the common dynein-1 regulators dynactin, LIS1, or BICD2 are not found in association with dynein-2. These data explain why mutations in either WDR34 or WDR60 cause disease as well as identifying TCTEX1D2 as a candidate ciliopathy gene.
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