The splicing-factor Prp40 affects dynein-dynactin function in Aspergillus nidulans.

The splicing-factor Prp40 affects dynein-dynactin function in Aspergillus nidulans.

Mol Biol Cell. 2020 Apr 08;:mbcE20030166

Authors: Qiu R, Zhang J, Xiang X

Abstract
The multi-component cytoplasmic dynein transports cellular cargoes with the help of another multi-component complex dynactin, but we do not know enough about factors that may affect the assembly and functions of these proteins. From a genetic screen for mutations affecting early-endosome distribution in Aspergillus nidulans, we identified the prp40AL438* mutation in Prp40A, a homolog of Prp40, an essential RNA-splicing factor in the budding yeast. Prp40A is not essential for splicing, although it associates with the nuclear splicing machinery. The prp40AL438* mutant is much healthier than the ∆prp40A mutant, but both mutants exhibit similar defects in dynein-mediated early endosome transport and nuclear distribution. In the prp40AL438* mutant, the frequency but not the speed of dynein-mediated early endosome transport is decreased, which correlates with a decrease in the microtubule plus-end accumulations of dynein and dynactin. Within the dynactin complex, the actin-related protein Arp1 forms a mini-filament. In a pulldown assay, the amount of Arp1 pulled-down with its pointed-end protein Arp11 is lowered in the prp40AL438* mutant. In addition, we found from published interactome data that a mammalian Prp40 homolog PRPF40A interacts with Arp1. Thus, Prp40 homologs may regulate the assembly or function of dynein-dynactin and their mechanisms deserve to be further studied.

PMID: 32267207 [PubMed – as supplied by publisher]

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