Chlamydomonas cilia proteins

Axonemal dyneins are highly complex molecular motors that power ciliary motility. These multi-subunit enzymes are assembled at dedicated sites within the cytoplasm. At least nineteen cytosolic factors are specifically needed for the generation of dynein holoenzymes and/or their trafficking to the growing cilium. Many proteins are subject to N-terminal processing and acetylation which can generate degrons subject to the AcN-end rule and alter N-terminal electrostatics, generate new binding interfaces, and affect subunit stoichiometry through targeted degradation. Here we have used mass spectrometry of cilia samples and electrophoretically purified dynein heavy chains from Chlamydomonas to define their N-terminal processing; we also detail the N-terminal acetylase complexes present in this organism. We identify four classes of dynein heavy chain based on their processing pathways by two distinct acetylases one of which is dependent on methionine aminopeptidase activity. In addition, we fi...