id: P78953
gene_symbol: mid1
product_type: PROTEIN
status: DRAFT
taxon:
  id: NCBITaxon:284812
  label: Schizosaccharomyces pombe (strain 972 / ATCC 24843)
description: >-
  Anillin-related scaffold protein (also called Dmf1) that positions the
  cytokinetic division plane in fission yeast. During interphase Mid1 is
  predominantly nuclear; at the onset of mitosis it is exported from the nucleus
  and forms a broad cortical band of punctate "nodes" at the cell middle,
  overlying the nucleus, thereby coupling the future division site to nuclear
  position. Mid1 serves as a recruitment platform that brings contractile
  actomyosin ring (CAR) components - myosin-II (Myo2), the IQGAP Rng2, the F-BAR
  protein Cdc15, formin Cdc12, the SAD-family kinase Cdr2, and the Clp1/Cdc14
  phosphatase - to the medial cortex, where these nodes condense into the
  contractile ring. Mid1 binds the plasma membrane through a C-terminal
  C2-pleckstrin-homology (PH) module that prefers PI(4,5)P2 and through an
  amphipathic helix adjacent to its nuclear localization signal; its
  intrinsically disordered N-terminal half oligomerizes and can undergo liquid-
  liquid phase separation, properties suited to scaffolding other node proteins.
  Mid1 localization and activity are cell-cycle regulated by phosphorylation:
  Plo1 (polo-like kinase) phosphorylation promotes its nuclear export and ring
  competence, and the septation initiation network kinase Sid2 phosphorylates
  Mid1 to remove it from the cortex at the onset of ring constriction.
existing_annotations:
- term:
    id: GO:0000281
    label: mitotic cytokinesis
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: >-
      Mid1 is a well-established participant in mitotic cytokinesis, positioning
      the division plane and scaffolding contractile-ring assembly. The
      phylogenetic (IBA) involvement in mitotic cytokinesis is fully consistent
      with extensive experimental data in S. pombe and with the anillin family.
    action: ACCEPT
    reason: >-
      Phylogenetic inference matches the abundant experimental evidence that
      mid1 acts in mitotic cytokinesis; this is a non-core but accurate parent
      process term for the gene.
    supported_by:
    - reference_id: PMID:22918943
      supporting_text: >-
        orderly assembly of the contractile ring in wild-type cells depends on
        Mid1p to recruit myosin-II, Rng2p, and Cdc15p to nodes and to place
        cytokinetic nodes around the cell equator.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005826
    label: actomyosin contractile ring
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 localizes to and is active in the medial actomyosin contractile ring.
      Experimental S. pombe data place Mid1 in the mitotic contractile ring;
      the phylogenetic localization is correct, although the more specific
      mitotic-ring terms (GO:0110085) are also annotated experimentally.
    action: ACCEPT
    reason: >-
      Consistent with experimental IDA annotations to mitotic actomyosin
      contractile ring; the IBA general term is accurate.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        Plo1p localizes to the spindle pole bodies and spindles of mitotic
        cells and also to the medial ring at the time of its formation.
      reference_section_type: ABSTRACT
- term:
    id: GO:0000915
    label: actomyosin contractile ring assembly
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: >-
      Mid1 is required for orderly assembly of the contractile ring by
      recruiting ring components to medial nodes. The phylogenetic involvement
      in contractile ring assembly is accurate; the organism-specific mitotic
      term (GO:1903475) is also annotated experimentally.
    action: ACCEPT
    reason: >-
      Matches experimental IMP evidence for ring assembly; appropriate general
      process term.
    supported_by:
    - reference_id: PMID:16864655
      supporting_text: >-
        the anillin-like protein Mid1p establishes a broad band of small dots
        or nodes in the cortex near the nucleus. These nodes mature by the
        addition of conventional myosin II (Myo2p, Cdc4p, and Rlc1p), IQGAP
        (Rng2p), pombe Cdc15 homology protein (Cdc15p), and formin (Cdc12p).
      reference_section_type: ABSTRACT
- term:
    id: GO:0031106
    label: septin ring organization
  evidence_type: IBA
  original_reference_id: GO_REF:0000033
  qualifier: involved_in
  review:
    summary: >-
      Septin ring organization is the characterized function of the paralog
      mid2 (anillin-like, SPCC18B5.04), not of mid1. Mid1 organizes the
      contractile actomyosin ring and division-site nodes, but there is no
      experimental evidence that it organizes the septin ring. This IBA term
      most likely reflects mis-propagation across the anillin family and a
      mid1/mid2 conflation.
    action: REMOVE
    reason: >-
      No experimental support for mid1 in septin ring organization; this is the
      established role of the paralog mid2. The phylogenetic propagation
      conflates the two pombe anillins and over-annotates mid1.
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: >-
      Mid1 is nuclear during interphase, so nuclear localization is correct.
      This IEA term is redundant with multiple experimental IDA nucleus
      annotations but is accurate.
    action: ACCEPT
    reason: >-
      Nuclear localization is experimentally documented; the subcellular-
      location-derived IEA is corroborated.
    supported_by:
    - reference_id: PMID:8946912
      supporting_text: >-
        In wild-type cells, Dmf1p is nuclear during interphase, and relocates
        to form a medial ring at the cell cortex coincident with the onset of
        mitosis.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005856
    label: cytoskeleton
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: >-
      The generic "cytoskeleton" term is an imprecise UniProt subcellular-
      location mapping. Mid1's relevant cytoskeletal location is the actomyosin
      contractile ring / cortical nodes, captured by more specific experimental
      terms (GO:0110085, GO:0071341). The broad term should be replaced by the
      specific structures.
    action: MODIFY
    reason: >-
      "cytoskeleton" is uninformatively general; experimentally Mid1 is in the
      mitotic actomyosin contractile ring and medial cortical nodes.
    proposed_replacement_terms:
    - id: GO:0110085
      label: mitotic actomyosin contractile ring
    - id: GO:0071341
      label: medial cortical node
    supported_by:
    - reference_id: PMID:16864655
      supporting_text: >-
        the anillin-like protein Mid1p establishes a broad band of small dots
        or nodes in the cortex near the nucleus.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005938
    label: cell cortex
  evidence_type: IEA
  original_reference_id: GO_REF:0000044
  qualifier: located_in
  review:
    summary: >-
      Mid1 localizes to the medial cell cortex, so the cortex term is correct
      but general. The more specific experimentally supported terms are
      "medial cortex" (GO:0031097) and "medial cortical node" (GO:0071341).
    action: MODIFY
    reason: >-
      Accurate but imprecise; the medial cortex / medial cortical node terms
      are experimentally supported and more informative.
    proposed_replacement_terms:
    - id: GO:0031097
      label: medial cortex
    - id: GO:0071341
      label: medial cortical node
    supported_by:
    - reference_id: PMID:10930468
      supporting_text: >-
        mid1 protein (mid1p) shuttles between the nucleus and a cortical medial
        broad band during interphase and early mitosis.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: EXP
  original_reference_id: PMID:10930468
  qualifier: located_in
  review:
    summary: >-
      Direct experimental localization shows Mid1 shuttles between the nucleus
      and a cortical medial band. Nuclear localization during interphase is
      well documented in this study, including NLS/NES mutational analysis.
    action: ACCEPT
    reason: >-
      Robust IDA/EXP nuclear localization with functional NLS/NES dissection.
    supported_by:
    - reference_id: PMID:10930468
      supporting_text: >-
        NES mutations caused mid1p accumulation in the nucleus and loss of
        function.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: EXP
  original_reference_id: PMID:12186944
  qualifier: located_in
  review:
    summary: >-
      Mid1/Dmf1 localization to the nucleus is consistent with the body of
      evidence. This study examined microtubule-dependent delays in Mid1/Dmf1
      cortical recruitment but also documents its nuclear pool.
    action: ACCEPT
    reason: >-
      Nuclear localization corroborated across many studies; accept.
    supported_by:
    - reference_id: PMID:12186944
      supporting_text: >-
        Microtubule depolymerisation also delayed the localisation of other CAR
        components such as actin and Mid1/Dmf1.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: EXP
  original_reference_id: PMID:19427212
  qualifier: located_in
  review:
    summary: >-
      Nuclear localization is central to this study, which shows that Mid1
      nuclear export links division-plane position to nuclear position. Accept.
    action: ACCEPT
    reason: >-
      Mid1 nuclear pool and its regulated export are directly demonstrated.
    supported_by:
    - reference_id: PMID:19427212
      supporting_text: >-
        the positive signaling from the nucleus is based on Mid1 nuclear
        export, which links division-plane position to nuclear position during
        early mitosis.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: EXP
  original_reference_id: PMID:19474789
  qualifier: located_in
  review:
    summary: >-
      Consistent with Mid1's interphase nuclear localization and its presence
      in medial cortical nodes. Accept the nucleus localization.
    action: ACCEPT
    reason: >-
      Nuclear localization corroborated; this study primarily characterizes
      Mid1 in cortical nodes with Cdr2/Wee1/Cdr1.
    supported_by:
    - reference_id: PMID:19474789
      supporting_text: >-
        This network is located at cortical nodes in the middle of interphase
        cells, and these nodes contain the Cdk1 inhibitor Wee1, the
        Wee1-inhibitory kinases Cdr1 (also known as Nim1) and Cdr2, and the
        anillin-like protein Mid1.
      reference_section_type: ABSTRACT
- term:
    id: GO:1903475
    label: mitotic actomyosin contractile ring assembly
  evidence_type: EXP
  original_reference_id: PMID:19075108
  qualifier: involved_in
  review:
    summary: >-
      Mid1 is required for mitotic actomyosin contractile ring assembly, a core
      function supported by many studies. The supporting publication
      (PMID:19075108) is not in the local cache and could not be read directly,
      but the annotated function is strongly corroborated by other experimental
      annotations (PMID:9852154 IMP, PMID:15184401 IMP, PMID:22918943).
    action: ACCEPT
    reason: >-
      Core function with overwhelming independent experimental support; the
      single uncached reference does not undermine an otherwise robust
      annotation.
    supported_by:
    - reference_id: PMID:22918943
      supporting_text: >-
        Ring assembly is unreliable and slow without Mid1p because the
        scattered Cdc12p nodes generate strands spread widely beyond the equator
      reference_section_type: ABSTRACT
- term:
    id: GO:0008289
    label: lipid binding
  evidence_type: EXP
  original_reference_id: PMID:15572668
  qualifier: enables
  review:
    summary: >-
      Mid1 binds the medial cortex membrane via its C-terminus, including an
      amphipathic helix predicted to insert into the lipid bilayer. Lipid
      binding is experimentally supported; the more specific PI(4,5)P2 binding
      (GO:0005546) is also annotated.
    action: ACCEPT
    reason: >-
      Direct membrane/lipid association demonstrated; general lipid binding is
      accurate.
    supported_by:
    - reference_id: PMID:15572668
      supporting_text: >-
        mid1p C-terminus association with the cortex requires a putative
        amphipathic helix adjacent to mid1p nuclear localization sequence (NLS),
        which is predicted to insert directly into the lipid bilayer.
      reference_section_type: ABSTRACT
- term:
    id: GO:1902408
    label: mitotic cytokinesis, division site positioning
  evidence_type: EXP
  original_reference_id: PMID:19427212
  qualifier: involved_in
  review:
    summary: >-
      This is a core function of Mid1: defining the position of the division
      plane at the medial cortex via nuclear export and Cdr2-dependent cortical
      anchoring. Strongly supported.
    action: ACCEPT
    reason: >-
      Directly demonstrated division-site positioning function.
    supported_by:
    - reference_id: PMID:19427212
      supporting_text: >-
        These signals control the localization of the anillin-like protein
        Mid1, which defines the position of the division plane at the medial
        cortex, where it recruits contractile-ring components at mitosis onset.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005546
    label: phosphatidylinositol-4,5-bisphosphate binding
  evidence_type: IDA
  original_reference_id: PMID:25959226
  qualifier: enables
  review:
    summary: >-
      Crystal structures and functional analysis show that Mid1 binds membranes
      through a cryptic C2 domain, and dimerization confers high affinity and
      preference for PI(4,5)P2, which anchors Mid1 at the division plane. This
      specific lipid-binding activity is well supported.
    action: ACCEPT
    reason: >-
      Direct biochemical/structural demonstration of PI(4,5)P2 binding.
    supported_by:
    - reference_id: PMID:25959226
      supporting_text: >-
        Dimerization of Mid1 leads to high affinity and preference for
        PI(4,5)P2, which stably anchors Mid1 at the division plane, bypassing
        the requirement for Rho GTPase.
      reference_section_type: ABSTRACT
- term:
    id: GO:0106006
    label: cytoskeletal protein-membrane anchor activity
  evidence_type: EXP
  original_reference_id: PMID:25959226
  qualifier: enables
  review:
    summary: >-
      Mid1 anchors the contractile (cytoskeletal) ring to the plasma membrane
      via its C2-PH membrane-binding module, a defining molecular function of
      anillin/Mid1 family scaffolds. Well supported.
    action: ACCEPT
    reason: >-
      Structural and functional data show Mid1 tethers the contractile ring to
      membrane lipids; appropriate MF term.
    supported_by:
    - reference_id: PMID:25959226
      supporting_text: >-
        Anillins and Mid1 are scaffold proteins that play key roles in
        anchorage of the contractile ring at the cell equator during
        cytokinesis in animals and fungi, respectively.
      reference_section_type: ABSTRACT
- term:
    id: GO:1902408
    label: mitotic cytokinesis, division site positioning
  evidence_type: EXP
  original_reference_id: PMID:15928091
  qualifier: involved_in
  review:
    summary: >-
      Division-site positioning is a core, repeatedly validated Mid1 function.
      The supporting paper (PMID:15928091, "Dynamic positioning of the fission
      yeast cell division plane") is not in the local cache, but the annotated
      function is independently and strongly supported by other experimental
      annotations (PMID:8946912, PMID:19427212, PMID:9852154).
    action: ACCEPT
    reason: >-
      Core function with extensive corroborating experimental evidence; the
      uncached reference does not weaken it.
    supported_by:
    - reference_id: PMID:8946912
      supporting_text: >-
        Dmf1 mutants complete mitosis and initiate septum formation, but the
        septa that form are positioned at random locations and angles in the
        cell, rather than in the middle.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:31243991
  qualifier: enables
  review:
    summary: >-
      Bare "protein binding" is uninformative. The interactor here (Myo2,
      UniProtKB:Q9USI6) reflects Mid1's role in recruiting/anchoring myosin-II
      to nodes, which is better captured by the protein-membrane adaptor /
      scaffold molecular functions. Keep only as supporting interaction
      evidence, not as an informative MF.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Generic protein binding term provides no functional insight; the
      meaningful activity (scaffolding/anchoring Myo2) is captured by more
      specific terms such as GO:0043495 and GO:0140693.
    supported_by:
    - reference_id: PMID:31243991
      supporting_text: >-
        Mid1p recruits in succession myosin-II (Myo2p heavy chain, Cdc4p light
        chain, Rlc1p1 regulatory light chain together called Myo2, UniProtKB
        Q9USI6), IQGAP Rng2p, F-BAR protein (FER/CDP4 homology
        domain-Bin-Amphiphysin-Rvs-like protein) Cdc15p and formin Cdc12p
      reference_section_type: INTRODUCTION
- term:
    id: GO:0140693
    label: molecular condensate scaffold activity
  evidence_type: IDA
  original_reference_id: PMID:31243991
  qualifier: enables
  review:
    summary: >-
      The intrinsically disordered N-terminal half of Mid1 (Mid1p-N452) demixes
      into liquid droplets and has properties suited to scaffolding other node
      proteins. This molecular condensate scaffold activity is directly
      supported.
    action: ACCEPT
    reason: >-
      Purified Mid1 N-terminus undergoes phase separation with scaffolding
      properties, consistent with its role in organizing cytokinetic nodes.
    supported_by:
    - reference_id: PMID:31243991
      supporting_text: >-
        Purified Mid1p-N452 demixes into liquid droplets at concentrations far
        below its concentration in nodes. These physical properties are
        appropriate for scaffolding other proteins in nodes.
      reference_section_type: ABSTRACT
- term:
    id: GO:0106006
    label: cytoskeletal protein-membrane anchor activity
  evidence_type: EXP
  original_reference_id: PMID:21376595
  qualifier: enables
  review:
    summary: >-
      Mid1 anchors actomyosin-ring components to the medial cortex by recruiting
      them to membrane-associated nodes. This study shows Mid1 recruits Rng2 to
      cortical nodes, consistent with a cytoskeletal protein-membrane anchor
      function. Accept.
    action: ACCEPT
    reason: >-
      Supports Mid1's role in tethering ring components at the cortex via nodes.
    supported_by:
    - reference_id: PMID:21376595
      supporting_text: >-
        Mid1p arrives first at the medial cortex and recruits actomyosin ring
        components to node-like structures
      reference_section_type: ABSTRACT
- term:
    id: GO:0106006
    label: cytoskeletal protein-membrane anchor activity
  evidence_type: IPI
  original_reference_id: PMID:15184401
  qualifier: enables
  review:
    summary: >-
      Mid1 anchors dephosphorylated Myo2 (the cytoskeletal motor) at the medial
      cortex (membrane), directly supporting cytoskeletal protein-membrane
      anchor activity. The IPI interactor is Myo2 (PomBase:SPCC645.05c).
    action: ACCEPT
    reason: >-
      Physical anchoring of Myo2 at the cortex is directly demonstrated.
    supported_by:
    - reference_id: PMID:15184401
      supporting_text: >-
        dephosphorylated Myo2 is anchored by Mid1 at the medial cortex and
        promotes the ring assembly in cooperation with F-actin.
      reference_section_type: ABSTRACT
- term:
    id: GO:1903475
    label: mitotic actomyosin contractile ring assembly
  evidence_type: IMP
  original_reference_id: PMID:15184401
  qualifier: involved_in
  review:
    summary: >-
      Mid1 is required for proper accumulation of Myo2 and ring placement; loss
      of Mid1 spatial function impairs contractile ring assembly. Core function,
      strongly supported by IMP.
    action: ACCEPT
    reason: >-
      Direct mutant phenotype evidence for Mid1's role in ring assembly via
      Myo2 anchoring.
    supported_by:
    - reference_id: PMID:15184401
      supporting_text: >-
        The accumulation of Myo2 requires the anillin homologue Mid1 that
        functions in proper ring placement.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:8946912
  qualifier: is_active_in
  review:
    summary: >-
      The founding study showing Dmf1/Mid1 is nuclear during interphase and
      relocates to a medial cortical ring at mitosis onset. Nuclear
      localization is directly observed.
    action: ACCEPT
    reason: >-
      Original IDA demonstration of interphase nuclear localization.
    supported_by:
    - reference_id: PMID:8946912
      supporting_text: >-
        In wild-type cells, Dmf1p is nuclear during interphase, and relocates
        to form a medial ring at the cell cortex coincident with the onset of
        mitosis.
      reference_section_type: ABSTRACT
- term:
    id: GO:0031097
    label: medial cortex
  evidence_type: IDA
  original_reference_id: PMID:8946912
  qualifier: is_active_in
  review:
    summary: >-
      Mid1/Dmf1 forms a medial cortical ring/band at mitosis onset. Medial
      cortex localization is directly observed and is a core localization for
      its division-site positioning function.
    action: ACCEPT
    reason: >-
      Original IDA evidence for medial cortex localization.
    supported_by:
    - reference_id: PMID:8946912
      supporting_text: >-
        relocates to form a medial ring at the cell cortex coincident with the
        onset of mitosis.
      reference_section_type: ABSTRACT
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:22918943
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 is a defining component of medial cortical (cytokinetic) nodes that
      mature into the contractile ring. Directly observed in live-cell imaging.
      Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging shows Mid1 in cortical nodes that condense into the ring.
    supported_by:
    - reference_id: PMID:22918943
      supporting_text: >-
        cortical nodes containing the protein Blt1p and several kinases appear
        early in G2, mature into cytokinetic nodes by adding anillin Mid1p,
        myosin-II, formin Cdc12p, and other proteins, and condense into a
        contractile ring
      reference_section_type: ABSTRACT
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:30853434
  qualifier: enables
  review:
    summary: >-
      Bare "protein binding" with interactor PomBase:SPAC31A2.16 (Sid2/Mob1 SIN
      kinase complex). The biologically meaningful relationship is that Sid2
      phosphorylates Mid1 to remove it from the cortex; the generic MF term is
      uninformative.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Uninformative generic term; the meaningful interaction (Sid2-mediated
      regulation) is better represented as a phosphorylation/regulatory
      relationship rather than as a molecular function of mid1.
    supported_by:
    - reference_id: PMID:30853434
      supporting_text: >-
        We report that the terminal SIN kinase, Sid2 [6], phosphorylates Mid1 to drive its
        removal from the cortex at CR constriction onset.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:30853434
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 nuclear localization is consistent with its documented interphase
      nuclear pool. Accept.
    action: ACCEPT
    reason: >-
      Nuclear localization corroborated across studies.
    supported_by:
    - reference_id: PMID:30853434
      supporting_text: >-
        The anillin-like protein Mid1 localizes to nodes and is required for CR
        assembly at mid-cell
      reference_section_type: ABSTRACT
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:30853434
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 localizes to medial cortical (interphase/cytokinetic) nodes; this
      study shows Sid2 phosphorylation controls its node/cortex residence.
      Directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1 in nodes; central to the study.
    supported_by:
    - reference_id: PMID:30853434
      supporting_text: >-
        A Mid1 mutant that cannot be phosphorylated by Sid2 remains cortical
        during cytokinesis, over-accumulates in interphase nodes following cell
        division
      reference_section_type: ABSTRACT
- term:
    id: GO:0110085
    label: mitotic actomyosin contractile ring
  evidence_type: IDA
  original_reference_id: PMID:30853434
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 localizes to the mitotic contractile ring before being removed at
      constriction onset. Directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1 at the contractile ring.
    supported_by:
    - reference_id: PMID:30853434
      supporting_text: >-
        When CR constriction begins, Mid1 leaves the division site.
      reference_section_type: ABSTRACT
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:16864655
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 establishes a broad band of cortical nodes in the medial cortex,
      directly observed by live-cell imaging. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1-established medial cortical nodes.
    supported_by:
    - reference_id: PMID:16864655
      supporting_text: >-
        the anillin-like protein Mid1p establishes a broad band of small dots
        or nodes in the cortex near the nucleus.
      reference_section_type: ABSTRACT
- term:
    id: GO:0110085
    label: mitotic actomyosin contractile ring
  evidence_type: IDA
  original_reference_id: PMID:16864655
  qualifier: is_active_in
  review:
    summary: >-
      Mid1-established nodes coalesce into the mitotic contractile ring; Mid1 is
      a ring-resident component during assembly. Directly observed.
    action: ACCEPT
    reason: >-
      Direct imaging places Mid1 in nodes that form the contractile ring.
    supported_by:
    - reference_id: PMID:16864655
      supporting_text: >-
        The nodes coalesce laterally into a compact ring when Cdc12p and
        profilin Cdc3p stimulate actin polymerization.
      reference_section_type: ABSTRACT
- term:
    id: GO:1903475
    label: mitotic actomyosin contractile ring assembly
  evidence_type: IGI
  original_reference_id: PMID:16687577
  qualifier: involved_in
  review:
    summary: >-
      Genetic interaction with cdc15 (PomBase:SPAC20G8.05c) shows ring formation
      upon metaphase arrest depends on Mid1 when Cdc15 is nonfunctional,
      supporting Mid1's role in mitotic ring assembly. Accept.
    action: ACCEPT
    reason: >-
      Genetic-interaction evidence consistent with Mid1's core ring-assembly
      function.
    supported_by:
    - reference_id: PMID:16687577
      supporting_text: >-
        In the absence of functional Cdc15p, ring formation upon metaphase
        arrest depends on the anillin-like Mid1p.
      reference_section_type: ABSTRACT
- term:
    id: GO:0120104
    label: mitotic actomyosin contractile ring, proximal layer
  evidence_type: IDA
  original_reference_id: PMID:28914606
  qualifier: is_active_in
  review:
    summary: >-
      Super-resolution/FRET mapping places membrane-binding scaffolds (which
      include Mid1) in the membrane-proximal layer (0-80 nm) of the contractile
      ring. The specific proximal-layer localization is directly supported.
    action: ACCEPT
    reason: >-
      Nanoscale architecture analysis localizes Mid1 to the membrane-proximal
      ring layer.
    supported_by:
    - reference_id: PMID:28914606
      supporting_text: >-
        The most membrane-proximal layer (0-80 nm) is composed of
        membrane-binding scaffolds, formin, and the tail of the essential
        myosin-II.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:14602073
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 migrates from the nucleus to specify the division-site band; nuclear
      localization is directly observed in this temporal-pathway study. Accept.
    action: ACCEPT
    reason: >-
      Direct imaging of the nuclear Mid1 pool prior to cortical migration.
    supported_by:
    - reference_id: PMID:14602073
      supporting_text: >-
        the anillin-like protein (Mid1p) migrates from the nucleus and specifies
        a broad band of cortex around the equator as the division site.
      reference_section_type: ABSTRACT
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:14602073
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 specifies a broad band of cortical nodes at the equator early in the
      cytokinesis pathway. Directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1-specified equatorial cortical band/nodes.
    supported_by:
    - reference_id: PMID:14602073
      supporting_text: >-
        the anillin-like protein (Mid1p) migrates from the nucleus and specifies
        a broad band of cortex around the equator as the division site.
      reference_section_type: ABSTRACT
- term:
    id: GO:0031106
    label: septin ring organization
  evidence_type: IMP
  original_reference_id: PMID:15385632
  qualifier: involved_in
  review:
    summary: >-
      This IMP annotation cites PMID:15385632. Unlike the abstract-only cases where we
      defer to curators, this paper's FULL TEXT is cached and was checked directly: it
      contains zero mentions of mid1 and six of mid2, and characterizes S. pombe septins
      (Spns1-4) together with the anillin Mid2p. Septin ring organization is the
      established function of the paralog mid2 (SPCC18B5.04); Mid1 instead positions the
      actomyosin contractile ring and division-site nodes. On the strength of this
      full-text check this looks like a mid1/mid2 paralog conflation, flagged for PomBase
      re-assignment to mid2.
    action: REMOVE
    reason: >-
      Full text of the cited paper (cached, verified) discusses septins and Mid2p with no
      mention of mid1; septin ring organization is a mid2 function and Mid1 has no
      experimental role there. This is a verified full-text contradiction (not an
      abstract-only inference), so REMOVE is warranted; flagged for curator re-assignment
      to the paralog mid2.
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:19474789
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 is a documented component of medial cortical nodes that also contain
      Wee1, Cdr1 and Cdr2. Directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct evidence for Mid1 in interphase medial cortical nodes.
    supported_by:
    - reference_id: PMID:19474789
      supporting_text: >-
        This network is located at cortical nodes in the middle of interphase
        cells, and these nodes contain the Cdk1 inhibitor Wee1, the
        Wee1-inhibitory kinases Cdr1 (also known as Nim1) and Cdr2, and the
        anillin-like protein Mid1.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:18378776
  qualifier: enables
  review:
    summary: >-
      Bare "protein binding" with interactor PomBase:SPAC1782.09c (Clp1/Flp1).
      The meaningful relationship is that Mid1 tethers the Clp1/Cdc14
      phosphatase at the contractile ring via its scaffold function; the generic
      MF term is uninformative.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Generic protein binding term is uninformative; Mid1's scaffolding/anchor
      activity is captured by GO:0043495 and GO:0140693.
    supported_by:
    - reference_id: PMID:18378776
      supporting_text: >-
        Clp1/Flp1 is tethered at the contractile ring (CR) through its
        association with anillin-related Mid1.
      reference_section_type: ABSTRACT
- term:
    id: GO:0110085
    label: mitotic actomyosin contractile ring
  evidence_type: IDA
  original_reference_id: PMID:18378776
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 is anchored at the cell midzone/contractile ring and serves as a
      scaffold tethering Clp1. Direct FRAP-based evidence that Mid1 is stably
      anchored in the ring. Core localization.
    action: ACCEPT
    reason: >-
      Direct evidence (FRAP) for Mid1 anchored at the contractile ring/midzone.
    supported_by:
    - reference_id: PMID:18378776
      supporting_text: >-
        Mid1, unlike other tested CR components, is anchored at the cell
        midzone, and this physical property is likely to account for its
        scaffolding role.
      reference_section_type: ABSTRACT
- term:
    id: GO:0071341
    label: medial cortical node
  evidence_type: IDA
  original_reference_id: PMID:24790095
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 is present in interphase/cytokinetic nodes together with Blt1; this
      study of Blt1 documents Mid1 node localization. Directly observed. Core
      localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1 in cortical nodes in the context of Blt1 function.
    supported_by:
    - reference_id: PMID:24790095
      supporting_text: >-
        proteins that contribute to the cytokinetic contractile ring accumulate
        during interphase in nodes-precursor structures around the equatorial
        cortex.
      reference_section_type: ABSTRACT
- term:
    id: GO:0110085
    label: mitotic actomyosin contractile ring
  evidence_type: IDA
  original_reference_id: PMID:24790095
  qualifier: is_active_in
  review:
    summary: >-
      Mid1-containing nodes condense into the contractile ring; Mid1 is a ring
      component during assembly. Directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging places Mid1 in nodes that condense to the ring.
    supported_by:
    - reference_id: PMID:24790095
      supporting_text: >-
        During mitosis, additional proteins join these nodes, which condense to
        form the contractile ring.
      reference_section_type: ABSTRACT
- term:
    id: GO:0090488
    label: polo box domain specific binding
  evidence_type: IPI
  original_reference_id: PMID:9852154
  qualifier: enables
  review:
    summary: >-
      Mid1 interacts with polo kinase Plo1 (PomBase:SPAC23C11.16), which acts in
      a common pathway with Mid1 and is required for Mid1 nuclear exit and ring
      formation. Mid1 is phosphorylated by Cdk1 to create a polo-box docking
      site, supporting specific polo-box-domain binding. This is an informative,
      specific molecular function.
    action: ACCEPT
    reason: >-
      Two-hybrid and genetic data support a specific Mid1-Plo1 (polo box)
      interaction central to regulation of Mid1.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        Genetic and two-hybrid analyses suggest that Plo1p and Mid1p act in a
        common pathway distinct from that involving Pom1p.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005515
    label: protein binding
  evidence_type: IPI
  original_reference_id: PMID:9852154
  qualifier: enables
  review:
    summary: >-
      Bare "protein binding" with interactor Plo1 (PomBase:SPAC23C11.16). This
      is redundant with, and less informative than, the specific
      polo-box-domain binding annotation from the same paper.
    action: MARK_AS_OVER_ANNOTATED
    reason: >-
      Uninformative generic term, redundant with the specific GO:0090488
      annotation for the same Plo1 interaction.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        Genetic and two-hybrid analyses suggest that Plo1p and Mid1p act in a
        common pathway distinct from that involving Pom1p.
      reference_section_type: ABSTRACT
- term:
    id: GO:0005634
    label: nucleus
  evidence_type: IDA
  original_reference_id: PMID:9852154
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 is nuclear during interphase and requires Plo1 for nuclear exit;
      nuclear localization directly observed. Accept.
    action: ACCEPT
    reason: >-
      Direct evidence for the nuclear Mid1 pool; Plo1 controls its export.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        Plo1p is required for Mid1p to exit the nucleus and form a ring
      reference_section_type: ABSTRACT
- term:
    id: GO:0110085
    label: mitotic actomyosin contractile ring
  evidence_type: IDA
  original_reference_id: PMID:9852154
  qualifier: is_active_in
  review:
    summary: >-
      Mid1 coalesces into the medial ring (contractile ring) before anaphase;
      directly observed. Core localization.
    action: ACCEPT
    reason: >-
      Direct imaging of Mid1 forming the medial contractile ring.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        Mid1p first forms a diffuse cortical band during spindle formation and
        then coalesces into a ring before anaphase.
      reference_section_type: ABSTRACT
- term:
    id: GO:1903475
    label: mitotic actomyosin contractile ring assembly
  evidence_type: IMP
  original_reference_id: PMID:9852154
  qualifier: involved_in
  review:
    summary: >-
      mid1 mutants show defective placement and organization of the medial
      ring, with ring formation initiating near cell poles; Mid1 functions in
      recruiting ring components to the cell center. Core function, supported by
      mutant phenotype.
    action: ACCEPT
    reason: >-
      Mutant-phenotype evidence for Mid1 in contractile ring assembly/placement.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        ring formation is frequently initiated near the cell poles, indicating
        that Mid1p and Plo1p function in recruiting medial ring components to
        the cell center.
      reference_section_type: ABSTRACT
- term:
    id: GO:1902408
    label: mitotic cytokinesis, division site positioning
  evidence_type: IMP
  original_reference_id: PMID:9852154
  qualifier: involved_in
  review:
    summary: >-
      mid1 mutants mis-place the division site, demonstrating Mid1's role in
      positioning the cell-division site. Core function, supported by mutant
      phenotype.
    action: ACCEPT
    reason: >-
      Mutant-phenotype evidence for division-site positioning.
    supported_by:
    - reference_id: PMID:9852154
      supporting_text: >-
        the data indicate that Plo1p plays a role in the positioning of division
        sites by regulating Mid1p.
      reference_section_type: ABSTRACT
- term:
    id: GO:0031097
    label: medial cortex
  evidence_type: IDA
  original_reference_id: PMID:20870879
  qualifier: is_active_in
  review:
    summary: >-
      In a survey of polarity/division proteins during invasive filament
      growth, Mid1 localizes similarly in filaments and single cells (medial
      cortex). This is a high-content localization study; medial cortex
      localization is consistent with all prior data.
    action: ACCEPT
    reason: >-
      Consistent with established medial cortex localization of Mid1.
    supported_by:
    - reference_id: PMID:20870879
      supporting_text: >-
        A third group acting at different stages of the cell cycle, including
        Bud6, Rga4, and Mid1, localize similarly in filaments and single cells
      reference_section_type: ABSTRACT
- term:
    id: GO:0005635
    label: nuclear envelope
  evidence_type: HDA
  original_reference_id: PMID:16823372
  qualifier: is_active_in
  review:
    summary: >-
      This high-throughput ORFeome localization study (HDA) assigned a nuclear
      envelope signal. Mid1's robust, focused experimental data place it in the
      nucleoplasm/nucleus during interphase and at the medial cortex/ring;
      nuclear-envelope as a distinct functional compartment is not supported by
      focused studies and is likely a coarse high-throughput call reflecting the
      nuclear pool. Best kept as non-core pending verification.
    action: KEEP_AS_NON_CORE
    reason: >-
      Single high-throughput annotation; the nuclear-envelope signal probably
      reflects the well-documented nuclear pool rather than a specific
      nuclear-envelope function. Retain as non-core, not as a core localization.
    supported_by:
    - reference_id: PMID:8946912
      supporting_text: >-
        In wild-type cells, Dmf1p is nuclear during interphase
      reference_section_type: ABSTRACT
core_functions:
- description: >-
    Molecular scaffold / protein-membrane adaptor that anchors and recruits
    contractile-actomyosin-ring components (Myo2, Rng2, Cdc15, Cdc12, Cdr2,
    Clp1) to membrane-associated medial cortical nodes, building the recruitment
    platform for ring assembly.
  supported_by:
  - reference_id: PMID:22918943
    supporting_text: >-
      orderly assembly of the contractile ring in wild-type cells depends on
      Mid1p to recruit myosin-II, Rng2p, and Cdc15p to nodes and to place
      cytokinetic nodes around the cell equator.
    reference_section_type: ABSTRACT
  - reference_id: PMID:15184401
    supporting_text: >-
      dephosphorylated Myo2 is anchored by Mid1 at the medial cortex and
      promotes the ring assembly in cooperation with F-actin.
    reference_section_type: ABSTRACT
- description: >-
    Specification and positioning of the mitotic cell-division site: Mid1
    defines the medial division plane at the cell cortex by coupling cortical
    node position to nuclear position through cell-cycle-regulated nuclear
    export and Cdr2-dependent cortical anchoring.
  supported_by:
  - reference_id: PMID:19427212
    supporting_text: >-
      These signals control the localization of the anillin-like protein Mid1,
      which defines the position of the division plane at the medial cortex,
      where it recruits contractile-ring components at mitosis onset.
    reference_section_type: ABSTRACT
  - reference_id: PMID:8946912
    supporting_text: >-
      Dmf1 mutants complete mitosis and initiate septum formation, but the septa
      that form are positioned at random locations and angles in the cell,
      rather than in the middle.
    reference_section_type: ABSTRACT
- description: >-
    Membrane anchoring of the contractile ring via a C-terminal C2-PH module
    that binds PI(4,5)P2 (dimerization-enhanced) and an amphipathic helix that
    inserts into the lipid bilayer, tethering the cytoskeletal ring to the
    plasma membrane at the division plane.
  supported_by:
  - reference_id: PMID:25959226
    supporting_text: >-
      Dimerization of Mid1 leads to high affinity and preference for PI(4,5)P2,
      which stably anchors Mid1 at the division plane, bypassing the requirement
      for Rho GTPase.
    reference_section_type: ABSTRACT
  - reference_id: PMID:15572668
    supporting_text: >-
      We propose that membrane-bound oligomers of mid1p assemble recruitment
      "platforms" for cytokinetic ring components at the medial cortex and
      stabilize the ring position during its compaction.
    reference_section_type: ABSTRACT
- description: >-
    Molecular condensate scaffold activity: the intrinsically disordered
    N-terminal half oligomerizes and undergoes liquid-liquid phase separation,
    providing the scaffolding properties that organize cytokinetic nodes.
  supported_by:
  - reference_id: PMID:31243991
    supporting_text: >-
      Purified Mid1p-N452 demixes into liquid droplets at concentrations far
      below its concentration in nodes. These physical properties are
      appropriate for scaffolding other proteins in nodes.
    reference_section_type: ABSTRACT
proposed_new_terms: []
suggested_questions:
- question: >-
    How do nuclear export (CRM1/NES-dependent) and Cdr2-dependent cortical
    anchoring quantitatively combine to read out nuclear position and translate
    it into division-plane position?
- question: >-
    What is the precise contribution of Mid1 phase separation versus
    stoichiometric protein-protein interactions to node formation and stability
    in vivo?
suggested_experiments:
- description: >-
    Optogenetic or chemically inducible control of Mid1 nuclear export to test,
    in real time, whether acute relocalization of Mid1 to defined cortical zones
    is sufficient to redirect the division plane.
- description: >-
    Reconstitute Mid1 (full-length and N-terminal disordered fragment) with
    PI(4,5)P2-containing supported lipid bilayers and purified Myo2/Rng2/Cdc15
    to measure how phase separation and membrane binding cooperate to recruit
    ring components.
references:
- id: GO_REF:0000033
  title: Annotation inferences using phylogenetic trees
  findings: []
- id: GO_REF:0000044
  title: Gene Ontology annotation based on UniProtKB/Swiss-Prot Subcellular Location vocabulary mapping, accompanied by conservative changes to GO terms applied by UniProt
  findings: []
- id: PMID:10930468
  title: Analysis of mid1p, a protein required for placement of the cell division site, reveals a link between the nucleus and the cell surface in fission yeast.
  findings:
  - statement: >-
      Mid1 shuttles between the nucleus and a cortical medial broad band whose
      position is linked to nuclear position; functional NLS and two
      CRM1-dependent NES sequences govern this shuttling.
    supporting_text: >-
      mid1 protein (mid1p) shuttles between the nucleus and a cortical medial
      broad band during interphase and early mitosis. The position of this broad
      band, which overlies the nucleus, is linked to nuclear position even in
      cells with displaced or multiple nuclei.
    reference_section_type: ABSTRACT
- id: PMID:12186944
  title: Cytokinetic actomyosin ring formation and septation in fission yeast are dependent on the full recruitment of the polo-like kinase Plo1 to the spindle pole body and a functional spindle assembly checkpoint.
  findings:
  - statement: >-
      Microtubule depolymerization delays cortical localization of Mid1/Dmf1
      and other CAR components, linking ring assembly to Plo1 loading on SPBs.
    supporting_text: >-
      Microtubule depolymerisation also delayed the localisation of other CAR
      components such as actin and Mid1/Dmf1.
    reference_section_type: ABSTRACT
- id: PMID:14602073
  title: Spatial and temporal pathway for assembly and constriction of the contractile ring in fission yeast cytokinesis.
  findings:
  - statement: >-
      Mid1 migrates from the nucleus >90 min before SPB separation and specifies
      a broad equatorial cortical band as the division site, ahead of other ring
      proteins.
    supporting_text: >-
      the anillin-like protein (Mid1p) migrates from the nucleus and specifies a
      broad band of cortex around the equator as the division site.
    reference_section_type: ABSTRACT
- id: PMID:15184401
  title: Myosin-II reorganization during mitosis is controlled temporally by its dephosphorylation and spatially by Mid1 in fission yeast.
  findings:
  - statement: >-
      Mid1 anchors dephosphorylated Myo2 at the medial cortex; Myo2 accumulation
      at the division site requires Mid1.
    supporting_text: >-
      The accumulation of Myo2 requires the anillin homologue Mid1 that
      functions in proper ring placement.
    reference_section_type: ABSTRACT
- id: PMID:15385632
  title: Requirements of fission yeast septins for complex formation, localization, and function.
  findings:
  - statement: >-
      This study concerns S. pombe septins (Spns1-4) and the anillin Mid2p;
      it does not address mid1. Septin ring organization is a mid2 function.
    supporting_text: >-
      Coalescence into ring structures requires Spn1p and Spn4p associate with
      at least one other septin subunit and the expression of Mid2p that is
      normally restricted to mitosis.
    reference_section_type: ABSTRACT
- id: PMID:15572668
  title: C-terminal anchoring of mid1p to membranes stabilizes cytokinetic ring position in early mitosis in fission yeast.
  findings:
  - statement: >-
      Mid1 binds the medial cortex via a C-terminal amphipathic helix (membrane
      insertion) and oligomerizes to assemble recruitment platforms that
      stabilize ring position.
    supporting_text: >-
      mid1p C-terminus association with the cortex requires a putative
      amphipathic helix adjacent to mid1p nuclear localization sequence (NLS),
      which is predicted to insert directly into the lipid bilayer.
    reference_section_type: ABSTRACT
- id: PMID:15928091
  title: Dynamic positioning of the fission yeast cell division plane.
  findings: []
- id: PMID:16687577
  title: Cell cycle-dependent roles for the FCH-domain protein Cdc15p in formation of the actomyosin ring in Schizosaccharomyces pombe.
  findings:
  - statement: >-
      Ring formation upon metaphase arrest depends on Mid1 when Cdc15 is
      nonfunctional, a genetic interaction supporting Mid1's ring-assembly role.
    supporting_text: >-
      In the absence of functional Cdc15p, ring formation upon metaphase arrest
      depends on the anillin-like Mid1p.
    reference_section_type: ABSTRACT
- id: PMID:16823372
  title: ORFeome cloning and global analysis of protein localization in the fission yeast Schizosaccharomyces pombe.
  findings:
  - statement: >-
      High-throughput ORFeome GFP localization survey; assigned a nuclear
      envelope signal to Mid1, likely reflecting its nuclear pool.
    supporting_text: >-
      ORFeome cloning and global analysis of protein localization in the fission
      yeast Schizosaccharomyces pombe.
    reference_section_type: TITLE
- id: PMID:16864655
  title: Assembly of the cytokinetic contractile ring from a broad band of nodes in fission yeast.
  findings:
  - statement: >-
      Mid1 establishes a broad band of cortical nodes that mature by addition of
      Myo2, Rng2, Cdc15 and Cdc12 and then coalesce into the contractile ring.
    supporting_text: >-
      the anillin-like protein Mid1p establishes a broad band of small dots or
      nodes in the cortex near the nucleus. These nodes mature by the addition
      of conventional myosin II (Myo2p, Cdc4p, and Rlc1p), IQGAP (Rng2p), pombe
      Cdc15 homology protein (Cdc15p), and formin (Cdc12p).
    reference_section_type: ABSTRACT
- id: PMID:18378776
  title: The Clp1/Cdc14 phosphatase contributes to the robustness of cytokinesis by association with anillin-related Mid1.
  findings:
  - statement: >-
      Mid1 is stably anchored at the cell midzone and tethers the Clp1/Cdc14
      phosphatase at the contractile ring, underlying its scaffolding role.
    supporting_text: >-
      Mid1, unlike other tested CR components, is anchored at the cell midzone,
      and this physical property is likely to account for its scaffolding role.
    reference_section_type: ABSTRACT
- id: PMID:19075108
  title: 'Assembly of normal actomyosin rings in the absence of Mid1p and cortical nodes in fission yeast.'
  findings: []
- id: PMID:19427212
  title: Spatial control of cytokinesis by Cdr2 kinase and Mid1/anillin nuclear export.
  findings:
  - statement: >-
      Cdr2 anchors Mid1 at the medial cortex during interphase; nuclear export
      links division-plane position to nuclear position in early mitosis.
    supporting_text: >-
      Cdr2 kinase anchors Mid1 at the medial cortex during interphase through
      association with the Mid1 N terminus.
    reference_section_type: ABSTRACT
- id: PMID:19474789
  title: A spatial gradient coordinates cell size and mitotic entry in fission yeast.
  findings:
  - statement: >-
      Mid1 is a component of medial cortical nodes that also contain Wee1, Cdr1
      and Cdr2, integrating cell-size sensing with the cell cycle.
    supporting_text: >-
      these nodes contain the Cdk1 inhibitor Wee1, the Wee1-inhibitory kinases
      Cdr1 (also known as Nim1) and Cdr2, and the anillin-like protein Mid1.
    reference_section_type: ABSTRACT
- id: PMID:20870879
  title: Reorganization of the growth pattern of Schizosaccharomyces pombe in invasive filament formation.
  findings:
  - statement: >-
      During invasive filament growth, Mid1 localizes similarly to single cells
      (medial cortex), unlike polarity factors that redistribute.
    supporting_text: >-
      a third group acting at different stages of the cell cycle, including
      Bud6, Rga4, and Mid1, localize similarly in filaments and single cells
    reference_section_type: ABSTRACT
- id: PMID:21376595
  title: IQGAP-related Rng2p organizes cortical nodes and ensures position of cell division in fission yeast.
  findings:
  - statement: >-
      Mid1 recruits Rng2 to cortical nodes; Rng2 then recruits other ring
      components, ensuring correct division-site placement.
    supporting_text: >-
      Mid1p recruits Rng2p to cortical nodes at the division site and that
      Rng2p, in turn, recruits other components of the actomyosin ring to
      cortical nodes
    reference_section_type: ABSTRACT
- id: PMID:22918943
  title: Anillin-related protein Mid1p coordinates the assembly of the cytokinetic contractile ring in fission yeast.
  findings:
  - statement: >-
      Orderly contractile-ring assembly depends on Mid1 to recruit Myo2, Rng2
      and Cdc15 to nodes and to place cytokinetic nodes around the cell equator.
    supporting_text: >-
      orderly assembly of the contractile ring in wild-type cells depends on
      Mid1p to recruit myosin-II, Rng2p, and Cdc15p to nodes and to place
      cytokinetic nodes around the cell equator.
    reference_section_type: ABSTRACT
- id: PMID:24790095
  title: Characterization of the roles of Blt1p in fission yeast cytokinesis.
  findings:
  - statement: >-
      Mid1 is present in interphase precursor nodes that condense into the
      contractile ring during mitosis.
    supporting_text: >-
      During mitosis, additional proteins join these nodes, which condense to
      form the contractile ring.
    reference_section_type: ABSTRACT
- id: PMID:25959226
  title: Mechanistic insights into the anchorage of the contractile ring by anillin and Mid1.
  findings:
  - statement: >-
      Mid1 binds membranes through a cryptic C2 domain; dimerization yields high
      affinity/preference for PI(4,5)P2, anchoring Mid1 at the division plane
      independently of Rho GTPase.
    supporting_text: >-
      Dimerization of Mid1 leads to high affinity and preference for PI(4,5)P2,
      which stably anchors Mid1 at the division plane, bypassing the requirement
      for Rho GTPase.
    reference_section_type: ABSTRACT
- id: PMID:28914606
  title: Nanoscale architecture of the Schizosaccharomyces pombe contractile ring.
  findings:
  - statement: >-
      Membrane-binding scaffolds (including Mid1) occupy the membrane-proximal
      layer (0-80 nm) of the contractile ring.
    supporting_text: >-
      The most membrane-proximal layer (0-80 nm) is composed of membrane-binding
      scaffolds, formin, and the tail of the essential myosin-II.
    reference_section_type: ABSTRACT
- id: PMID:30853434
  title: NDR Kinase Sid2 Drives Anillin-like Mid1 from the Membrane to Promote Cytokinesis and Medial Division Site Placement.
  findings:
  - statement: >-
      The SIN kinase Sid2 phosphorylates Mid1 to remove it from the cortex at
      constriction onset; Mid1 localizes to nodes, the contractile ring and the
      nucleus.
    supporting_text: >-
      the terminal SIN kinase, Sid2, phosphorylates Mid1 to drive its removal
      from the cortex at CR constriction onset.
    reference_section_type: ABSTRACT
- id: PMID:31243991
  title: The Functionally Important N-Terminal Half of Fission Yeast Mid1p Anillin Is Intrinsically Disordered and Undergoes Phase Separation.
  findings:
  - statement: >-
      The N-terminal half of Mid1 (residues 1-452) is intrinsically disordered
      and phase-separates into liquid droplets, properties suited to scaffolding
      node proteins.
    supporting_text: >-
      Purified Mid1p-N452 demixes into liquid droplets at concentrations far
      below its concentration in nodes. These physical properties are
      appropriate for scaffolding other proteins in nodes.
    reference_section_type: ABSTRACT
- id: PMID:8946912
  title: The dmf1/mid1 gene is essential for correct positioning of the division septum in fission yeast.
  findings:
  - statement: >-
      dmf1/mid1 is essential for correct septum positioning; Dmf1p is nuclear in
      interphase and relocates to a medial cortical ring at mitosis onset with
      increased phosphorylation.
    supporting_text: >-
      In wild-type cells, Dmf1p is nuclear during interphase, and relocates to
      form a medial ring at the cell cortex coincident with the onset of
      mitosis.
    reference_section_type: ABSTRACT
- id: PMID:9852154
  title: Role of polo kinase and Mid1p in determining the site of cell division in fission yeast.
  findings:
  - statement: >-
      Plo1 is required for Mid1 nuclear exit and ring formation; Plo1 and Mid1
      act in a common pathway to recruit medial ring components to the cell
      center.
    supporting_text: >-
      Plo1p is required for Mid1p to exit the nucleus and form a ring, and Pom1p
      is required for proper placement of the Mid1p ring.
    reference_section_type: ABSTRACT