To end, my favorite experiment from this paper. Poly(A)-binding protein (Pab1) puncta are readily visible in many filamentous fungi, but when we tagged the Pab1 ortholog in A. nidulans we could not see them. Using FRAP, we found they were obscured by a bright cytosolic signal! [7/7]

Thanks to my supervisors @ewjwallace.bsky.social and Ken Sawin for their support throughout my PhD! [6/7]

SsdA shares strong sequence similarity with S. cerevisiae Ssd1, a translational repressor. This raises the interesting possibility that SsdA puncta represent translationally repressed mRNPs, dissolved near tips to allow local regulation of translation during polarized growth. [5/7]

This tip-proximal depletion depends on NDR kinase CotA. Acute inhibition of an analog-sensitive CotA allele causes SsdA puncta to accumulate near tips. A nonphosphorylatable SsdA mutant shows the same phenotype. [4/7]

SsdA puncta are largely depleted near hyphal tips, despite early endosomes being abundant in the same region. We found that the extent of this depletion correlates with hyphal growth rate. [3/7]

SsdA puncta hitchhike on early endosomes via PxdA and DipA, adaptors previously characterized for peroxisome hitchhiking. This raises the possibility that they serve as a adaptors for different types of cargo. (SsdA in magenta and early endosomes in green) [2/7]