Activity-dependent local translation of CaMKII mRNA
The CaMKII mRNA has two 3'UTRs that are produced by alternative polyadenylation. We have shown that the long form is required for both activity-dependent accumulation of CaMKII protein and for enhancement of spontaneous release as the larval NMJ (Kuklin et al., 2017). In recent work, we have used CRISPR to generate animals that lack distal 3'UTR sequences and find that they are unable to form normal memory.
Calcium/calmodulin-dependent protein kinase II is a major component of synapses in both vertebrates and invertebrates. This kinase is critical to multiple forms of plasticity.
We use genetics, imaging and protein biochemistry to understand the complex regulation of this kinase and how it functions in plasticity. Specific areas of focus are listed below.
Role of the CaMKII 3' UTR in establishing the synaptic proteome
How subcellular compartments build unique proteomes is unknown. Using reporter transgenes, we have identified multiple cis elements in the 3'UTR of the the CaMKII gene that allow specific axonal accumulation of the CaMKII protein in adult mushroom body. Using CRISPR to delete these elements, we find they facilitate local translation by recruiting RNA-binding proteins which allow concentration of CaMKII in the synaptic region.
Regulation of subunit exchange and holoenzyme stability
Recent papers from the Kuriyan and Stratton labs support the possibility that subunit exchange can occur in the CaMKII holoenzyme. We are pursuing the role of this exchange in cell culture and using CRISPR-engineered flies with altered holoenzyme stability to determine if subunit exchange has a role in long-term memory.