Of the 39 unique key RBPs (the union of the top 20 motif-enriched RBPs from each tissue), only five (ESRP1, FUS, MBNL1, PCBP2, RBM8A) overlapped with a previously curated list of genes whose expression correlates with MLS9.
It could be useful to also assess proteomic data for these RBPs, as RNA abundance often doesn’t correlate with protein abundance, especially in the context of aging.
although alternative first exon (AF) was the second most frequent AS event, averaging 22.8% in a single species, comparable to cassette exon (Fig. 1b), none of these were conserved
Since maximum lifespan is not a conserved phenotype, it would be interesting to see if other types of splicing events (e.g. alternative first exons) are enriched for specific biological functions, irrespective of their conservation.
our data raise the possibility that TBC1D15 localized to mitochondria in neurons treated with LLOMe
Is it possible that under these conditions, neurons transfer damaged mitochondria and/or other cellular material to astrocytes? It could be interesting to do neuron-specific labeling prior to co-culturing to track mitochondria.
Thus, the lack of robust ESCRT recruitment is not simply attributed to insufficient protein expression in neurons.
I’m curious if you looked at CHMP2B levels by western blot in addition to immunofluorescence. Is it possible that neurons express alternate mRNA isoforms and/or proteoforms (e.g. truncated CHMP2B) that disrupt canonical ESCRT recruitment?