Figure 2.
Schematic of BMP signaling in promoting axon regeneration. BMP can activate a pro-regenerative transcriptional program through the Smad-mediated canonical pathway. Smad1 works together with histone-modifying enzymes to increase histone acetylation levels, which in turn facilitates Smad1 promoter binding and transcription of regeneration-associated genes (RAGs) by way of local chromatin relaxation. BMP also regulates local cytoskeletal assembly through non-canonical pathways, such as LIMK-cofilin signaling. Retrogradely transported signaling endosomes may control microtubule stability and link cytoskeletal and nuclear responses to BMPs.