Affinage

MICALL1

MICAL-like protein 1 · UniProt Q8N3F8

Length
863 aa
Mass
93.4 kDa
Annotated
2026-06-10
17 papers in source corpus 14 papers cited in narrative 14 extracted findings
Cross-family judge vs UniProt: Affinage preferred faithfulness: 8/8 claims corpus-supported (100%)

Mechanistic narrative

Synthesis pass · prose summary of the discoveries below

MICALL1 (MICAL-L1) is a multivalent membrane scaffold that organizes tubular recycling endosomes (TREs) and coordinates receptor recycling, with downstream consequences for cell migration, mitosis, and ciliogenesis (PMID:19864458, PMID:21951725). Its C-terminal coiled-coil region is necessary and sufficient for targeting to tubular membranes, and membrane association is reinforced by direct phosphatidic acid binding through C-terminal hydrophobic residues (PMID:19864458, PMID:23596323, PMID:34100897). MICAL-L1 acts as a Rab35 effector that bridges upstream GTPases to downstream traffic: Rab35 and Arf6 govern its endosomal recruitment, after which MICAL-L1 scaffolds the non-redundant downstream Rabs Rab8a, Rab13, and Rab36 onto recycling endosomes (PMID:21951725, PMID:25086062). On TREs it nucleates a fission and biogenesis machinery, partnering with the BAR-domain protein syndapin2 to drive membrane tubulation (PMID:23596323), and orchestrating sequential endosome fission by first recruiting FCHSD2 to trigger ARP2/3-mediated branched actin constriction and then EHD1 for nucleotide-hydrolysis-driven scission (PMID:19864458, PMID:39382837). It additionally scaffolds GRAF1 and the SH3-domain adaptors CD2AP and CIN85 to promote tubule vesiculation and recycling (PMID:25364729, PMID:40740057). Through this trafficking function MICAL-L1 supports growth-factor- and integrin-induced Src activation, focal adhesion turnover, and migration (PMID:24481818), and within endothelial junctions a PACSIN2/EHD4/MICAL-L1 complex directs VE-cadherin trafficking during angiogenesis (PMID:33972531). Beyond recycling, MICAL-L1 binds α/β- and γ-tubulin to anchor at centrosomes where it recruits EHD1 to drive CP110 removal and ciliogenesis (PMID:31615969), and is required for recycling-endosome-dependent cytokinesis and chromosome alignment in mitosis (PMID:25287187). MICALL1 is a transcriptional target of p53 that links DNA damage signaling to TRE biogenesis (PMID:28714518).

Mechanistic history

Synthesis pass · year-by-year structured walk · 13 steps
  1. 2009 High

    Established MICAL-L1 as the scaffold that physically links EHD1 and Rab8a on tubular recycling endosomes, answering how these recycling factors are co-recruited to tubular membranes.

    Evidence Reciprocal co-IP, domain truncation mapping the coiled-coil, siRNA knockdown, and transferrin/integrin recycling assays across cell lines

    PMID:19864458

    Open questions at the time
    • Did not define upstream GTPase control of MICAL-L1 recruitment
    • No structural detail of the coiled-coil membrane interaction
  2. 2011 High

    Placed MICAL-L1 within a GTPase hierarchy, showing Rab35 and Arf6 act upstream to control its endosomal recruitment and that MICAL-L1/Arf6 lie upstream of Rab8a.

    Evidence Co-IP, siRNA knockdown, and active/inactive GTPase mutant overexpression with fluorescence microscopy

    PMID:21951725

    Open questions at the time
    • Mechanism by which active Rab35 displaces MICAL-L1 from TREs not resolved
    • Single lab
  3. 2013 High

    Defined the lipid basis of TRE membrane association, showing MICAL-L1 and syndapin2 bind phosphatidic acid and cooperate to nucleate tubulation.

    Evidence Lipid-binding assays, in vitro liposome tubulation with recombinant syndapin2, and co-IP

    PMID:23596323

    Open questions at the time
    • In vivo contribution of phosphatidic acid to TRE biogenesis not quantified
    • Did not map the MICAL-L1 lipid-binding residues (later addressed in #10)
  4. 2014 Medium

    Showed MICAL-L1 scaffolds multiple non-redundant downstream Rabs (Rab8, Rab13, Rab36) during NGF-induced neurite outgrowth, with Rab36/JIP4 having a distinct functional output.

    Evidence siRNA knockdown of Rab35/MICAL-L1/Rab8/Rab13/Rab36 and neurite outgrowth assays in PC12 cells

    PMID:25086062

    Open questions at the time
    • Direct binding of each Rab to MICAL-L1 not biochemically dissected
    • Generality beyond NGF/PC12 system unknown
  5. 2014 Medium

    Identified GRAF1 as a MICAL-L1/EHD1-associated factor driving TRE vesiculation, linking the scaffold to membrane scission.

    Evidence Co-IP, knockdown, and a semi-permeabilized cell vesiculation assay with purified EHD1 and GRAF1

    PMID:25364729

    Open questions at the time
    • Order of GRAF1 versus other fission factors not established
    • Single lab
  6. 2014 Medium

    Connected MICAL-L1 trafficking function to Src activation, focal adhesion turnover, and migration, defining a physiological output of TRE recycling.

    Evidence siRNA knockdown of MICAL-L1/EHD1, Src activation, focal adhesion turnover, and migration assays in HeLa and fibroblasts

    PMID:24481818

    Open questions at the time
    • Direct cargo-binding mechanism for Src vesicles not shown
    • Single lab
  7. 2014 Medium

    Revealed mitotic roles, including an EHD1-independent function in chromosome alignment and an EHD1-dependent recycling role in cytokinesis.

    Evidence Differential siRNA knockdown of MICAL-L1 and EHD1 with binucleation, chromosome alignment, and microtubule dynamics readouts

    PMID:25287187

    Open questions at the time
    • Molecular partner for the EHD1-independent mitotic function unidentified
    • Mechanism linking MICAL-L1 to microtubule dynamics unclear
  8. 2017 Medium

    Identified MICALL1 as a direct p53 transcriptional target, linking DNA damage signaling to TRE biogenesis.

    Evidence Multi-omics, p53-binding motif identification ~3 kb upstream, siRNA depletion of p53/MICALL1, and co-localization with RAB8A/CD2AP

    PMID:28714518

    Open questions at the time
    • Functional consequence of p53-driven TRE biogenesis for DNA damage outcomes not established
    • Single lab
  9. 2019 Medium

    Extended MICAL-L1 function to the centrosome/cilium, showing it binds tubulins to anchor at centrioles and recruit EHD1 for CP110 removal and ciliogenesis.

    Evidence siRNA knockdown with ciliogenesis phenotypes, mass spectrometry, and direct binding assays to α/β- and γ-tubulin

    PMID:31615969

    Open questions at the time
    • How a recycling scaffold also acts at centrioles mechanistically distinct from TREs unclear
    • Single lab
  10. 2021 Medium

    Demonstrated a junctional PACSIN2/EHD4/MICAL-L1 complex controlling VE-cadherin trafficking, polarized endothelial migration, and angiogenesis.

    Evidence Co-IP, knockdown, VE-cadherin trafficking assays, and angiogenesis sprouting assays in endothelial cells

    PMID:33972531

    Open questions at the time
    • Whether this is the same TRE machinery repurposed at junctions not fully resolved
    • Single lab
  11. 2021 Medium

    Mapped C-terminal hydrophobic residues required for phosphatidic acid binding and defined the RBD contribution to PACSIN-mediated tubulation and surface cargo delivery.

    Evidence shRNA knockdown, synchronized secretion assay, in vitro tubulation with recombinant MICAL-L1-RBD, STORM imaging, and site-directed mutagenesis

    PMID:34100897

    Open questions at the time
    • Identity of the affected cargo subset incompletely defined
    • Golgi association mechanism not detailed
  12. 2024 Medium

    Resolved the sequential logic of endosome fission, showing MICAL-L1 recruits FCHSD2/ARP2/3 for early actin-driven constriction before EHD1-mediated scission.

    Evidence Co-IP, siRNA knockdown of MICAL-L1/FCHSD2, ARP2/3 actin branching, endosome fission, and recycling assays

    PMID:39382837

    Open questions at the time
    • Temporal coordination measured indirectly
    • Single lab
  13. 2025 Medium

    Added CD2AP and CIN85 as SH3-domain-recruited TRE constituents acting through the actin cytoskeleton in recycling.

    Evidence Co-IP mapping SH3 interactions, siRNA knockdown of CD2AP/CIN85, and receptor recycling assays

    PMID:40740057

    Open questions at the time
    • Direct actin-cytoskeleton link inferred, not demonstrated
    • Single lab

Open questions

Synthesis pass · forward-looking unresolved questions
  • How MICAL-L1's many partner interactions are spatially and temporally segregated across TREs, centrosomes, junctions, and the mitotic apparatus remains unresolved.
  • No structural model of the multivalent scaffold with bound partners
  • Regulation of context-specific complex assembly unknown
  • Whether disease-relevant phenotypes arise from MICALL1 loss not established

Mechanism profile

Synthesis pass · controlled-vocabulary classification · explore literature graph →
Molecular activity
GO:0060090 molecular adaptor activity 6 GO:0008289 lipid binding 2 GO:0008092 cytoskeletal protein binding 1
Localization
GO:0005768 endosome 6 GO:0005794 Golgi apparatus 1 GO:0005815 microtubule organizing center 1 GO:0005929 cilium 1
Pathway
R-HSA-5653656 Vesicle-mediated transport 4 R-HSA-9609507 Protein localization 3 R-HSA-1852241 Organelle biogenesis and maintenance 1
Complex memberships
MICAL-L1/EHD1/GRAF1 complexMICAL-L1/EHD1/Rab8a TRE scaffoldPACSIN2/EHD4/MICAL-L1 junctional complex

Evidence

Reading pass · 14 per-paper findings extracted from the source corpus
Year Finding Method Journal Conf PMIDs
2009 MICAL-L1 directly interacts with EHD1 and Rab8a, colocalizing on tubular recycling endosomes. The MICAL-L1 C-terminal coiled-coil region is necessary and sufficient for localization to tubular membranes. MICAL-L1 depletion causes loss of EHD1-Rab8a interaction and absence of both proteins from tubular membranes, implicating MICAL-L1 as a scaffold/Rab effector that recruits and links EHD1 and Rab8a to tubular recycling endosomes to facilitate receptor recycling. Co-immunoprecipitation, live-cell imaging, siRNA knockdown, domain truncation experiments (coiled-coil region), transferrin and integrin receptor recycling assays Molecular biology of the cell High 19864458
2011 MICAL-L1 interacts with Rab35 and Arf6 in vivo. Active Rab35 overexpression impairs MICAL-L1 recruitment to tubular recycling endosomes, while Rab35 depletion enhances MICAL-L1 localization there. Arf6 forms a complex with MICAL-L1 and contributes to its endosomal recruitment. This positions Rab35 as a critical upstream regulator of MICAL-L1 and Arf6, with MICAL-L1 and Arf6 acting upstream of Rab8a. Co-immunoprecipitation, siRNA knockdown, overexpression of GTPase mutants (active/inactive), fluorescence microscopy Traffic (Copenhagen, Denmark) High 21951725
2013 MICAL-L1 and the BAR-domain protein syndapin2 both bind phosphatidic acid (a novel lipid component of recycling endosomes). Direct protein-protein interaction between MICAL-L1 and syndapin2 stabilizes membrane association. Phosphatidic acid in liposomes enhances syndapin2-mediated membrane tubulation in vitro, supporting a model in which MICAL-L1 and syndapin2 cooperate to nucleate tubular recycling endosome biogenesis. Lipid-binding assays (phosphatidic acid), in vitro liposome tubulation assay with recombinant syndapin2, co-immunoprecipitation, siRNA knockdown Molecular biology of the cell High 23596323
2014 During NGF-induced neurite outgrowth, Rab35 recruits MICAL-L1 to Arf6-positive recycling endosomes, and MICAL-L1 in turn scaffolds Rab8, Rab13, and Rab36 to those endosomes. Knockdown of Rab36 impaired recruitment of the Rab36 effector JIP4 to recycling endosomes and inhibited neurite outgrowth without affecting Rab8 or Rab13 localization, demonstrating non-redundant downstream Rab functions. siRNA knockdown of Rab35, MICAL-L1, Rab8, Rab13, Rab36; fluorescence microscopy; neurite outgrowth assays in NGF-treated PC12 cells Biology open Medium 25086062
2014 GRAF1 forms a complex with MICAL-L1 and EHD1 at tubular recycling endosomes. GRAF1 overexpression causes vesiculation of MICAL-L1-positive tubules; GRAF1 depletion impairs tubular recycling endosome vesiculation and delays receptor recycling. Co-addition of purified EHD1 and GRAF1 in a semi-permeabilized cell assay produces synergistic tubule vesiculation. Co-immunoprecipitation, siRNA knockdown, overexpression, semi-permeabilized cell vesiculation assay with purified proteins Frontiers in cell and developmental biology Medium 25364729
2014 MICAL-L1 depletion results in increased binucleated cells due to impaired recycling endosome transport during late cytokinesis, and also causes aberrant chromosome alignment and lagging chromosomes independently of EHD1, indicating an EHD1-independent role for MICAL-L1 earlier in mitosis. Both MICAL-L1 and EHD1 differentially influence microtubule dynamics during early and late mitosis. siRNA knockdown of MICAL-L1 and EHD1, binucleation assays, chromosome alignment imaging, microtubule dynamics analysis Traffic (Copenhagen, Denmark) Medium 25287187
2014 MICAL-L1 is required for growth-factor- and integrin-induced Src activation and transport to the cell periphery. MICAL-L1 depletion impairs focal adhesion turnover, cell spreading, and migration. MICAL-L1-mediated recruitment of EHD1 to Src-containing recycling endosomes is required for Src release from the perinuclear recycling compartment in response to growth factor stimulation. siRNA knockdown of MICAL-L1 and EHD1, co-localization by fluorescence microscopy, Src activation assays, focal adhesion turnover assays, migration assays in HeLa cells and human fibroblasts Journal of cell science Medium 24481818
2017 MICALL1 is a transcriptional target of p53; functional p53-binding motifs were identified ~3000 bp upstream of the MICALL1 gene. In response to DNA damage, MICALL1 co-localizes with RAB8A and CD2AP at tubular recycling endosomes; siRNA depletion of p53 or MICALL1 prevents this localization, demonstrating that p53 regulates tubular recycling endosome biogenesis via MICALL1. Multi-omics (mass spectrometry, cDNA microarray), p53 binding motif identification, siRNA knockdown, co-localization by fluorescence microscopy International journal of oncology Medium 28714518
2019 MICAL-L1 localizes to cilia and centrosomes (including non-ciliated cells). MICAL-L1 knockdown impairs ciliogenesis similarly to EHD1 knockdown, prevents CP110 removal from the mother centriole, and causes EHD1 to fail to localize to basal bodies. Mass spectrometry and direct binding assays identified α-tubulin–β-tubulin heterodimers and γ-tubulin as direct MICAL-L1 interaction partners, supporting a model in which centriolar tubulins anchor MICAL-L1 to recruit EHD1 for ciliogenesis. siRNA knockdown, fluorescence microscopy (localization to cilia/centrosomes), mass spectrometry, direct protein-binding assays (tubulin interactions) Journal of cell science Medium 31615969
2021 PACSIN2 recruits EHD4 and MICAL-L1 to the rear end of asymmetric adherens junctions in endothelial cells, forming a recycling endosome-like tubular structure. This junctional PACSIN2/EHD4/MICAL-L1 complex controls local VE-cadherin trafficking and coordinates polarized endothelial migration and angiogenesis. Co-immunoprecipitation, fluorescence microscopy, siRNA/shRNA knockdown, VE-cadherin trafficking assays, angiogenesis sprouting assays Nature communications Medium 33972531
2021 MICAL-L1 depletion impairs delivery of a subset of cargo proteins to the cell surface. The MICAL-L1 RBD domain contributes to PACSIN-mediated membrane tubulation in vitro. Two hydrophobic residues at the MICAL-L1 C-terminus are important for phosphatidic acid binding and for association with membrane tubules. MICAL-L1 associates with Golgi apparatus markers and recycling endosomes. shRNA knockdown, synchronized secretion assay, in vitro membrane tubulation assay with recombinant MICAL-L1-RBD, confocal and STORM super-resolution microscopy, site-directed mutagenesis of C-terminal hydrophobic residues Biology open Medium 34100897
2024 MICAL-L1 directly interacts with FCHSD2 and recruits it to the endosomal membrane. FCHSD2 recruitment by MICAL-L1 is required for ARP2/3-mediated branched actin generation, endosome fission, and receptor recycling. Because MICAL-L1 recruits FCHSD2 prior to EHD1, MICAL-L1 orchestrates the sequential steps of endosomal fission by bridging early actin-driven constriction (via FCHSD2/ARP2/3) and subsequent nucleotide hydrolysis/fission (via EHD1). Co-immunoprecipitation, siRNA knockdown of MICAL-L1 and FCHSD2, ARP2/3 actin branching assays, endosome fission assays, receptor recycling assays Molecular biology of the cell Medium 39382837
2025 CD2AP and CIN85 are novel constituents of tubular recycling endosomes recruited by MICAL-L1 via their SH3 domains. Depletion of either CD2AP or CIN85 impairs recycling endosome function. MICAL-L1 scaffolding of these proteins likely impacts recycling through effects on the actin cytoskeleton. Co-immunoprecipitation (SH3 domain interactions), siRNA knockdown of CD2AP and CIN85, receptor recycling assays, fluorescence microscopy Traffic (Copenhagen, Denmark) Medium 40740057
2014 MICAL-L1 is necessary for ETEN (elongated tubular endosomal network) remodeling originating from the endocytic recycling compartment in human dendritic cells, as demonstrated by knockdown experiments. siRNA knockdown, fluorescence microscopy Communicative & integrative biology Low 26478765

Source papers

Stage 0 corpus · 17 papers · ranked by NIH iCite citations
Year Title Journal Citations PMID
2009 MICAL-L1 links EHD1 to tubular recycling endosomes and regulates receptor recycling. Molecular biology of the cell 151 19864458
2011 MICAL-L1 is a tubular endosomal membrane hub that connects Rab35 and Arf6 with Rab8a. Traffic (Copenhagen, Denmark) 91 21951725
2013 Cooperation of MICAL-L1, syndapin2, and phosphatidic acid in tubular recycling endosome biogenesis. Molecular biology of the cell 89 23596323
2014 Rab35 promotes the recruitment of Rab8, Rab13 and Rab36 to recycling endosomes through MICAL-L1 during neurite outgrowth. Biology open 71 25086062
2014 GRAF1 forms a complex with MICAL-L1 and EHD1 to cooperate in tubular recycling endosome vesiculation. Frontiers in cell and developmental biology 37 25364729
2021 A junctional PACSIN2/EHD4/MICAL-L1 complex coordinates VE-cadherin trafficking for endothelial migration and angiogenesis. Nature communications 34 33972531
2019 MICAL-L1 coordinates ciliogenesis by recruiting EHD1 to the primary cilium. Journal of cell science 24 31615969
2010 MICAL-L1: An unusual Rab effector that links EHD1 to tubular recycling endosomes. Communicative & integrative biology 23 20585517
2014 Novel functions for the endocytic regulatory proteins MICAL-L1 and EHD1 in mitosis. Traffic (Copenhagen, Denmark) 22 25287187
2012 Trafficking cascades mediated by Rab35 and its membrane hub effector, MICAL-L1. Communicative & integrative biology 18 23060965
2014 Regulation of Src trafficking and activation by the endocytic regulatory proteins MICAL-L1 and EHD1. Journal of cell science 17 24481818
2014 MICAL-L1-related and unrelated mechanisms underlying elongated tubular endosomal network (ETEN) in human dendritic cells. Communicative & integrative biology 10 26478765
2017 Regulation of tubular recycling endosome biogenesis by the p53-MICALL1 pathway. International journal of oncology 8 28714518
2024 Endosomal actin branching, fission, and receptor recycling require FCHSD2 recruitment by MICAL-L1. Molecular biology of the cell 4 39382837
2021 MICAL-L1 is required for cargo protein delivery to the cell surface. Biology open 4 34100897
2025 CIN85 and CD2AP Are Novel Constituents of Dynamic Tubular Recycling Endosomes That Regulate Recycling Upon Recruitment by MICAL-L1. Traffic (Copenhagen, Denmark) 3 40740057
2024 Endosomal actin branching, fission and receptor recycling require FCHSD2 recruitment by MICAL-L1. bioRxiv : the preprint server for biology 0 38979241

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