Evidence map›Paper›PMID 41943871›Full record

ArticleJournal of cell science2026

Endosomal maturation is controlled by the trimeric Bulli-Mon1-Ccz1 Rab7 GEF complex and the Rab5 GTPase-activating protein GAPsec.

Maren Janz, Maik Drechsler, Heiko Meyer, Vikeraman Sriram, Kim Michelle Simes, Elisa Frommhold, Nadia Füllbrunn, Lars Langemeyer, Christian Ungermann, Daniel Kümmel and 1 more

Abstract read
In one paragraph

Article in Journal of cell science, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Maren JanzOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.ORCID 0000-0002-0348-9046
Maik DrechslerOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.ORCID 0000-0001-7484-6365
Heiko MeyerOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.ORCID 0000-0002-3304-4523
Vikeraman SriramUniversity of Münster, Institute of Biochemistry, 48149 Münster, Germany.ORCID 0000-0003-2250-4595
Kim Michelle SimesOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.
Elisa FrommholdOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.
Nadia FüllbrunnOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.ORCID 0000-0003-1263-3166
Lars LangemeyerCenter for Cellular Nanoanalytics (CellNanOs), Osnabrück University, 49076 Osnabrück, Germany.ORCID 0000-0002-4309-0910
Christian UngermannCenter for Cellular Nanoanalytics (CellNanOs), Osnabrück University, 49076 Osnabrück, Germany.ORCID 0000-0003-4331-8695
Daniel KümmelUniversity of Münster, Institute of Biochemistry, 48149 Münster, Germany.ORCID 0000-0003-3950-5914
Achim PaululatOsnabrück University, Department of Biology/Chemistry, Zoology & Developmental Biology, 49076 Osnabrück, Germany.ORCID 0000-0002-8845-6859

Funding

Deutsche Forschungsgemeinschaft KU 2531/7-1Deutsche Forschungsgemeinschaft KU2531/7-1Deutsche Forschungsgemeinschaft PA 517/12-1Deutsche Forschungsgemeinschaft PA 517/12-2Deutsche Forschungsgemeinschaft PA517/12-2Deutsche Forschungsgemeinschaft UN 111/10-1Deutsche Forschungsgemeinschaft UN 111/9-1Deutsche Forschungsgemeinschaft UN 111/9-2Deutsche Forschungsgemeinschaft UN111/9-2Deutscher Akademischer AustauschdienstLand Niedersachsen ZN2832SFB 1557Sonderforschungsbereich 1557Sonderforschungsbereich TP10Sonderforschungsbereich TP12Sonderforschungsbereich TP14Sonderforschungsbereich TPZ2Universität Osnabrück
6 · The paper itself

Abstract

The endolysosomal system is crucial for the degradation of cellular waste in the lysosomal lumen. Within this pathway, endosomes mature prior to their fusion with lysosomes. This process relies on the sequential action of the CORVET and HOPS tethering complexes, guided by Rab5 and Rab7 GTPases, respectively. CORVET acts on early endosomes (EEs), whereas HOPS acts on maturing late endosomes and/or multivesicular bodies (LEs/MVBs) for lysosomal fusion. This process is finely tuned by the Rab-activating guanine nucleotide exchange factor (GEF) and the inactivating GTPase-activating protein (GAP). The BuMC1-GEF complex (Bulli-Mon1-Ccz1) uniquely activates Rab7 in metazoans and interacts with Rab5, which stimulates its activity. Here, we have identified GAPsec as a previously unreported GAP that activates Rab5 and is required for endosomal maturation in fruit fly nephrocytes. Inactivation of GAPsec results in enlarged, dysfunctional endosomes that are unable to reach lysosomes for degradation. Our study highlights the importance of coordinated Rab regulation for efficient endosomal trafficking.

Indexed as

Drosophila ProteinsEndosomesGTPase-Activating ProteinsGuanine Nucleotide Exchange Factorsrab5 GTP-Binding Proteinsrab GTP-Binding ProteinsAnimalsDrosophila melanogasterLysosomesrab7 GTP-Binding ProteinsDrosophila ProteinsGTPase-Activating ProteinsGuanine Nucleotide Exchange Factorsrab5 GTP-Binding Proteinsrab7 GTP-Binding Proteinsrab GTP-Binding ProteinsBulliBuMC1 complexEndosomal maturationGAPsecNephrocytesRab GTPasesTbc1d22

Identifiers

PMID41943871
PMCPMC13245906

What OpenQuestion holds

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.