ADAM11

ADAM11 is a catalytically inactive transmembrane disintegrin that functions as a neuronal adhesion and channel-organizing scaffold rather than a sheddase, lacking a functional zinc-binding motif in its metalloproteinase-like domain and the canonical RGD sequence in its disintegrin-like domain (PMID:9693107, PMID:10433968). Its principal characterized role is in the cerebellum, where ADAM11 is required to localize Kv1.1/Kv1.2 potassium channel complexes to the basket cell pinceau terminal; in its absence Kv1 channels are lost from the distal terminal, abolishing ephaptic inhibitory synchronization of Purkinje cell firing while sparing GABAergic release, identifying ADAM11 as a Kv1-interacting protein essential for presynaptic channel clustering (PMID:26269648). Consistent with a synaptic scaffolding function, ADAM11 binds the LGI proteins LGI1 and LGI4 and co-assembles with Caspr2 (CNTNAP2), ADAM22, ADAM23, and Kv1 subunits in a brain synaptic complex (PMID:18974846, PMID:25707359). Through its disintegrin-like domain ADAM11 also acts as a ligand supporting integrin α4-dependent cell adhesion (PMID:28913673), and it engages Wnt and BMP4 pathway components to positively regulate BMP4 signaling and negatively regulate β-catenin activity during neural crest proliferation and migration (PMID:37766964, PMID:37398217). Loss of ADAM11 in mice produces deficits in spatial learning and motor coordination and reduced inflammatory pain responses without histological abnormality, indicating a functional synaptic rather than developmental role in the brain (PMID:16504143, PMID:16729981).

1. 1998 Medium

   Established that ADAM11 is not a protease, redirecting attention from sheddase activity to adhesion/ligand functions and framing all later mechanistic work.

   Evidence Sequence and comparative domain architecture analysis of cloned ADAM11

   PMID:10433968 PMID:9693107

   Open questions at the time

   • Inference is sequence-based, not biochemical demonstration of absent catalysis
   • Does not establish what the disintegrin domain binds
2. 2006 Medium

   Defined the in vivo phenotype: knockout mice have spatial learning and motor coordination deficits yet normal histology, locating ADAM11 function at the synapse rather than in development.

   Evidence Gene-targeted knockout mice with Morris water maze and rotarod testing

   PMID:16504143

   Open questions at the time

   • Behavioral deficits not linked to a molecular mechanism
   • Single lab
3. 2006 Medium

   Distinguished ADAM11's role in pain processing, showing it is required for inflammatory/tonic pain but not acute nociception.

   Evidence Knockout mice across formalin, acetic acid writhing, von Frey, and hot plate tests

   PMID:16729981

   Open questions at the time

   • Molecular basis of the pain phenotype not identified
   • Anatomical site of action unknown
4. 2006 Low

   Contrasted ADAM11 with paralog ADAM22, showing ADAM11 has only minor effect on glioma proliferation, arguing its disintegrin domain function is not anti-proliferative.

   Evidence BrdU incorporation and GST-disintegrin domain fusion treatment in glioma cells

   PMID:16385342

   Open questions at the time

   • Negative/minor result for ADAM11 specifically
   • Single lab, single method
5. 2008 Medium

   Identified LGI1 and LGI4 as ligands for ADAM11, embedding it in the LGI-ADAM brain signaling system.

   Evidence Immunoprecipitation, mass spectrometry, and quantitative cell-ELISA binding assay

   PMID:18974846

   Open questions at the time

   • ADAM11 binding was secondary to the main ADAM22 finding
   • Functional consequence of LGI binding to ADAM11 not tested
6. 2009 Low

   Showed ADAM11 binds LGI1 but lacks PDZ-interacting sequences, implying PSD-95-independent signaling in LGI1-related epilepsy.

   Evidence Brain LGI1-interactor screen with binding and PDZ-motif sequence analysis

   PMID:19796686

   Open questions at the time

   • ADAM11-specific interaction mechanism not fully characterized
   • Single lab
7. 2015 High

   Provided the defining mechanism: ADAM11 is essential for clustering Kv1.1/Kv1.2 channels at the cerebellar pinceau terminal to enable ephaptic inhibition of Purkinje cells.

   Evidence ADAM11 mutant mice with Kv1 immunohistochemistry, GABA release, and ephaptic electrophysiology

   PMID:26269648

   Open questions at the time

   • Direct physical interaction between ADAM11 and Kv1 subunits not biochemically resolved
   • Recruitment mechanism to the terminal unknown
8. 2015 Medium

   Placed ADAM11 in the Caspr2 synaptic interactome alongside ADAM22/23, LGI proteins, and Kv1 channels, defining its complex membership.

   Evidence Interaction proteomics (IP + mass spectrometry) from mouse hippocampus

   PMID:25707359

   Open questions at the time

   • ADAM11 is one of many interactors; direct vs indirect association unresolved
   • Stoichiometry and architecture of the complex unknown
9. 2017 Medium

   Demonstrated the disintegrin-like domain of catalytically inactive ADAM11 supports integrin α4-dependent adhesion, giving the domain a defined ligand activity.

   Evidence Cell adhesion assay with recombinant ADAM11 disintegrin domain and integrin α4 blocking antibodies

   PMID:28913673

   Open questions at the time

   • Physiological context of integrin α4 binding in brain not established
   • Single lab
10. 2023 Medium

    Extended ADAM11 function beyond the synapse, linking it to Wnt/BMP4 signaling control of neural crest proliferation and migration.

    Evidence Xenopus loss/gain-of-function, mass spectrometry of partners, β-catenin and BMP4 reporter assays, B16 melanoma cells

    PMID:37398217 PMID:37766964

    Open questions at the time

    • Direct molecular targets within Wnt/BMP4 pathways not pinpointed
    • Relevance to mammalian neural crest development not confirmed

• How ADAM11 is recruited to specialized axonal terminals and whether it directly contacts Kv1 channels versus acting through LGI/ADAM22-23/Caspr2 partners remains unresolved.
• No structural model of ADAM11 in the synaptic complex
• Direct ADAM11-Kv1 binding not biochemically demonstrated
• Mechanism connecting adhesion/ligand activity to channel clustering unknown