DPYSL4

DPYSL4 (CRMP3) is a multifunctional cytoskeletal regulator that links microtubule dynamics to neuronal morphogenesis and, independently, to mitochondrial energetics and cancer suppression (PMID:30061407, PMID:17785607, PMID:39938451). In its neuronal role, DPYSL4 is required for hippocampal CA1 dendrite arborization, spine formation, and long-term potentiation (PMID:17785607), a dendritogenic activity that depends on its C-terminus and on L-type voltage-gated calcium channel-dependent Ca2+ influx (PMID:23868973). At the molecular level it shapes the microtubule cytoskeleton through two opposing modes: full-length DPYSL4 inhibits tubulin polymerization and neurite outgrowth, whereas calpain cleavage generates an N-terminally truncated form that translocates to the nucleus and associates with vimentin to drive nuclear condensation (PMID:19559021); it also directly binds katanin p60 (KATNA1) via its D region engaging the KATNA1 MIT domain, enhancing microtubule-severing efficiency to promote neurite length and branching (PMID:39938451). In a distinct pathway, DPYSL4 is a p53 transcriptional target whose dihydropyrimidinase-like domain mediates association with mitochondrial supercomplexes, stimulating ATP production and oxygen consumption and suppressing cancer cell invasion and metastasis (PMID:30061407). In a cancer-promoting context it interacts with SEMA4C, which stabilizes DPYSL4 to drive α-tubulin deacetylation and colon cancer cell motility (PMID:35261797). DPYSL4 also regulates dental epithelial proliferation and differentiation during tooth germ morphogenesis (PMID:23630450).

1. 2000 Medium

   Established that CRMP3/DPYSL4 functions within protein complexes in brain, providing the first physical-partner context by linking it to a CRAM family protein and to tyrosine kinase activity.

   Evidence Co-expression and reciprocal co-IP in COS-7 cells plus IP of rat brain extracts coupled to tyrosine kinase activity assay

   PMID:10851247

   Open questions at the time

   • Identity of the associated tyrosine kinase not resolved
   • Functional consequence of the CRAM complex unknown
   • No structural mapping of the interaction
2. 2007 High

   Defined an in vivo neuronal requirement, showing DPYSL4 is needed for hippocampal dendrite morphogenesis, spine formation, and synaptic plasticity rather than being merely a brain-enriched marker.

   Evidence Targeted gene disruption in mice with Golgi staining, immunohistochemistry, and LTP electrophysiology

   PMID:17785607

   Open questions at the time

   • Molecular pathway connecting DPYSL4 to dendrite growth not defined in this study
   • Mechanism of LTP impairment unresolved
3. 2009 Medium

   Revealed a dual cytoskeletal mechanism in which full-length DPYSL4 inhibits tubulin polymerization while calpain cleavage redirects it to the nucleus to bind vimentin, connecting proteolytic processing to subcellular relocalization.

   Evidence In vitro tubulin polymerization assays, overexpression of full-length vs. truncated forms, nuclear pulldown/MS, and vimentin-null neuron experiments

   PMID:19559021

   Open questions at the time

   • Trigger and physiological context for calpain cleavage unclear
   • Functional consequence of nuclear vimentin association beyond condensation not defined
   • Single lab
4. 2013 Medium

   Mapped the dendritogenic activity to the C-terminus and tied DPYSL4-driven dendrite growth to L-type calcium channel-dependent Ca2+ influx, linking morphology to signaling.

   Evidence Deletional domain mapping, siRNA knockdown, L-type channel pharmacology, and Ca2+ imaging in hippocampal neurons

   PMID:23868973

   Open questions at the time

   • How the C-terminus couples to calcium channels mechanistically unknown
   • Direct binding partners mediating Ca2+ effect not identified
5. 2013 Medium

   Extended DPYSL4 function beyond neurons by showing it controls dental epithelial proliferation, polarization, and differentiation during tooth germ morphogenesis.

   Evidence Knockdown and overexpression in tooth germ with cellular phenotype and ameloblast marker analysis

   PMID:23630450

   Open questions at the time

   • Molecular effectors in epithelium not defined
   • Relationship to its cytoskeletal activities untested
6. 2018 High

   Identified a non-cytoskeletal role as a p53 target that engages mitochondrial supercomplexes through its dihydropyrimidinase-like domain to boost oxidative phosphorylation and suppress cancer invasion.

   Evidence ChIP-seq, CRISPR/siRNA knockdown, domain-deletion mutagenesis, mitochondrial co-fractionation, ATP/O2 assays, and xenograft/metastasis models

   PMID:30061407

   Open questions at the time

   • Identity of the supercomplex components contacted not resolved
   • Mechanism by which OXPHOS stimulation suppresses invasion unclear
7. 2022 Medium

   Assigned an α-tubulin deacetylase function stabilized by SEMA4C, defining a cancer-promoting axis that opposes the tumor-suppressive mitochondrial role.

   Evidence Co-IP of SEMA4C–CRMP3, tubulin acetylation Westerns, overexpression/neutralizing antibody, and HDAC inhibitor rescue in colon cancer cells

   PMID:35261797

   Open questions at the time

   • No in vitro deacetylase reconstitution to confirm direct enzymatic activity
   • Reconciliation with tumor-suppressive role in other contexts unaddressed
8. 2025 High

   Provided a direct biochemical mechanism for DPYSL4 in neurite growth by showing its D region binds the KATNA1 MIT domain to enhance microtubule-severing.

   Evidence GST pulldown, co-IP, domain-mapping mutants, in vitro microtubule-severing assays, and CRISPR knockout in hippocampal neurons

   PMID:39938451

   Open questions at the time

   • How severing enhancement integrates with the tubulin-polymerization-inhibiting activity unresolved
   • Regulation of the DPYSL4–KATNA1 interaction unknown

• How DPYSL4's opposing molecular activities—tubulin polymerization inhibition, katanin-enhanced severing, α-tubulin deacetylation, and mitochondrial supercomplex association—are coordinated and switched between contexts remains unresolved.
• No unifying model linking cytoskeletal and mitochondrial roles
• Context-dependent tumor-suppressive vs. tumor-promoting behavior unexplained
• Upstream regulation of calpain processing and SEMA4C stabilization unmapped