TY  - JOUR
AU  - Hoffmann, Christian
AU  - Ruff, Kiersten M
AU  - Edu, Irina A
AU  - Shinn, Min Kyung
AU  - Tromm, Johannes V
AU  - King, Matthew R
AU  - Pant, Avnika
AU  - Ausserwöger, Hannes
AU  - Morgan, Jennifer R
AU  - Knowles, Tuomas P J
AU  - Pappu, Rohit V
AU  - Milovanovic, Dragomir
TI  - Synapsin Condensation is Governed by Sequence-Encoded Molecular Grammars.
JO  - Journal of molecular biology
VL  - 437
IS  - 8
SN  - 0022-2836
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - DZNE-2025-00426
SP  - 168987
PY  - 2025
AB  - Multiple biomolecular condensates coexist at the pre- and post- synapse to enable vesicle dynamics and controlled neurotransmitter release in the brain. In pre-synapses, intrinsically disordered regions (IDRs) of synaptic proteins are drivers of condensation that enable clustering of synaptic vesicles (SVs). Using computational analysis, we show that the IDRs of SV proteins feature evolutionarily conserved non-random compositional biases and sequence patterns. Synapsin-1 is essential for condensation of SVs, and its C-terminal IDR has been shown to be a key driver of condensation. Focusing on this IDR, we dissected the contributions of two conserved features namely the segregation of polar and proline residues along the linear sequence, and the compositional preference for arginine over lysine. Scrambling the blocks of polar and proline residues weakens the driving forces for forming micron-scale condensates. However, the extent of clustering in subsaturated solutions remains equivalent to that of the wild-type synapsin-1. In contrast, substituting arginine with lysine significantly weakens both the driving forces for condensation and the extent of clustering in subsaturated solutions. Co-expression of the scrambled variant of synapsin-1 with synaptophysin results in a gain-of-function phenotype in cells, whereas arginine to lysine substitutions eliminate condensation in cells. We report an emergent consequence of synapsin-1 condensation, which is the generation of interphase pH gradients that is realized via differential partitioning of protons between coexisting phases. This pH gradient is likely to be directly relevant for vesicular ATPase functions and the loading of neurotransmitters. Our studies highlight how conserved IDR grammars serve as drivers of synapsin-1 condensation.
KW  - Synapsins: metabolism
KW  - Synapsins: chemistry
KW  - Synapsins: genetics
KW  - Synaptic Vesicles: metabolism
KW  - Humans
KW  - Intrinsically Disordered Proteins: metabolism
KW  - Intrinsically Disordered Proteins: chemistry
KW  - Intrinsically Disordered Proteins: genetics
KW  - Animals
KW  - Amino Acid Sequence
KW  - Arginine: metabolism
KW  - Arginine: chemistry
KW  - Synaptophysin: metabolism
KW  - Synaptophysin: genetics
KW  - Lysine: metabolism
KW  - interphase pH gradient (Other)
KW  - microfluidics (Other)
KW  - phase separation (Other)
KW  - synapse (Other)
KW  - synapsin 1 (Other)
KW  - Synapsins (NLM Chemicals)
KW  - Intrinsically Disordered Proteins (NLM Chemicals)
KW  - Arginine (NLM Chemicals)
KW  - Synaptophysin (NLM Chemicals)
KW  - Lysine (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:39947282
DO  - DOI:10.1016/j.jmb.2025.168987
UR  - https://pub.dzne.de/record/277530
ER  -