CENPL

CENPL encodes a constitutive centromere-associated network (CCAN) protein recruited to CENP-A nucleosomes as a CENP-A-nucleosome distal component of the NAC, where its disruption causes chromosome alignment and segregation failures incompatible with cell survival (PMID:16622419). CENPL functions as a scaffolding hub: it binds CENP-N and, together with CENP-K, mediates docking of the CENP-PORQU sub-complex to the CCAN (PMID:23028590), and it co-migrates with CENP-K within a soluble nucleoplasmic CCAN complex outside centromeres (PMID:29509805). At the kinetochore, CENPL is required for kinetochore microtubule stability, homogeneous poleward microtubule flux, and the kinetochore pushing force driving centrosome separation, such that its loss produces syntelic and merotelic attachments (PMID:22399803). Recruitment of the CENP-LN module is gated by cell cycle-dependent phosphorylation of both CENPL and CENP-N, with cycles of phosphorylation and dephosphorylation required for proper centromere localization and CCAN reorganization (PMID:35830614). Beyond its kinetochore role, CENPL is a transcriptional target acting downstream of E2F8 in homologous recombination repair of double-strand breaks and chemoresistance (PMID:38522807) and downstream of a KDM1A→ZFP64 epigenetic axis in cancer (PMID:39628712).

1. 2006 High

   Established that CENPL is a bona fide centromere protein by placing it within the CENP-A nucleosome-associated complex and showing its loss abolishes faithful chromosome segregation.

   Evidence AP-MS of CENP-A nucleosome complexes plus RNAi depletion with mitotic phenotype readout in human cells

   PMID:16622419

   Open questions at the time

   • Did not resolve which CCAN partners directly contact CENPL
   • Molecular basis of the segregation defect not defined
2. 2012 High

   Defined the specific mechanical contribution of CENPL by linking it to kinetochore microtubule stability, flux, and pushing force, explaining why its loss yields erroneous attachments.

   Evidence siRNA depletion with live-cell imaging quantifying centrosome separation, microtubule flux, and attachment geometry in human cells

   PMID:22399803

   Open questions at the time

   • Does not establish whether these defects are direct or downstream of CCAN disassembly
   • No structural mechanism for force generation
3. 2012 Medium

   Positioned CENPL as a scaffold by mapping it as the CENP-N binding partner that, with CENP-K, recruits the CENP-PORQU sub-complex to the CCAN.

   Evidence Fluorescent three-hybrid, FRET, and co-immunoprecipitation interaction mapping in mammalian cells

   PMID:23028590

   Open questions at the time

   • Interaction interfaces not resolved at residue level
   • Single lab; affinities not quantified
4. 2013 Medium

   Provided structural and biochemical insight via the yeast ortholog, revealing an elongated Iml3 fold, heterodimerization with the Chl4 (CENP-N) C-terminus, and low-affinity DNA binding by the heterodimer.

   Evidence X-ray crystallography of Iml3, pull-down domain mapping, and in vitro DNA-binding assays in yeast

   PMID:24311582

   Open questions at the time

   • Not directly demonstrated for human CENPL
   • Functional relevance of DNA binding in cells untested
5. 2018 Medium

   Showed that CENPL exists in a preassembled soluble CCAN pool, indicating complex formation precedes centromere docking.

   Evidence Fluorescence cross-correlation spectroscopy in living human interphase cells

   PMID:29509805

   Open questions at the time

   • Stoichiometry of the soluble complex not determined
   • Single method, single lab
6. 2022 High

   Identified the regulatory logic of CENPL recruitment, showing phosphorylation cycles on CENPL and CENP-N control CENP-LN complex formation and centromere localization across the cell cycle.

   Evidence Phosphomimetic and phospho-null mutagenesis with live-cell imaging and chromosome segregation assays

   PMID:35830614

   Open questions at the time

   • Responsible kinases and phosphatases not identified
   • Phosphosite occupancy in vivo not quantified
7. 2023 Low

   Reported a non-canonical role linking CENPL to MEK1/2-ERK1/2 signaling driving proliferation and glycolysis in hepatocellular carcinoma.

   Evidence Overexpression/knockdown plus MEK/ERK inhibitor treatment with proliferation and glycolysis assays in HCC cells

   PMID:37914022

   Open questions at the time

   • No direct CENPL-MEK interaction demonstrated; pharmacological inference only
   • Single lab, not independently confirmed
   • Mechanistic connection to kinetochore role unclear
8. 2024 Medium

   Placed CENPL downstream of E2F8 in homologous recombination repair and chemoresistance via a rescue epistasis relationship.

   Evidence Knockdown/overexpression of CENPL and E2F8 with HR repair and chemosensitivity assays in breast cancer cells

   PMID:38522807

   Open questions at the time

   • Molecular mechanism by which CENPL promotes HR not defined
   • Single lab
9. 2024 Medium

   Established transcriptional control of CENPL by a KDM1A→ZFP64 epigenetic axis driving ovarian cancer growth.

   Evidence ChIP for H3K9me2 at the ZFP64 promoter, knockdown/overexpression epistasis, and in vivo xenograft rescue

   PMID:39628712

   Open questions at the time

   • Direct ZFP64 binding at the CENPL promoter not shown
   • Downstream effector function of CENPL in this context unresolved

• How the kinetochore scaffolding role of CENPL mechanistically connects to its reported roles in HR repair, signaling, and cancer transcriptional programs remains unresolved.
• No unifying mechanism linking centromere function to DNA repair/proliferation roles
• Kinases regulating CENP-LN phosphorylation unidentified
• No human structural model of the CENPL-CENP-N interface