Molecular Mechanisms of Dynein and KIF1A in Cellular Transport

Abstract Cytoplasmic dynein and KIF1A are essential motor proteins responsible for long-distance intracellular transport, playing critical roles in cellular processes such as metabolism, neuronal migration, and cell division. Dysfunctions in these motors are linked to severe neurological disorders, underscoring the urgency to elucidate their molecular mechanisms. Despite significant advances, key knowledge gaps remain regarding dynein’s motor domain coordination under load, the distinct roles of its AAA+ ATPases (AAA1, AAA3, and AAA4) in force generation and long-distance transport, and the cooperative functions of multiple dyneins within the dynein-dynactin-adaptor (DDA) complex. Similarly, the mechanisms governing KIF1A’s stepping along microtubules, its activation from an autoinhibited state, and the cooperative function of multiple KIF1A motors under physiological loads are not fully understood. Over the next five years, our lab will employ cutting-edge techniques such as MINFLUX microscopy, single-molecule Förster resonance energy transfer (smFRET), and optical tweezers, alongside innovative biochemical approaches including unnatural amino acid labeling, to investigate these critical questions. By integrating structural insights with dynamic functional assays, we aim to uncover the mechanistic basis of motor protein coordination and ATPase activity, providing a comprehensive understanding of how dynein and KIF1A sustain long-distance transport under physiological conditions. These findings will advance our fundamental knowledge of cellular transport mechanisms and inform the development of targeted therapies for motor protein-related neurological disorders.