Decision letter: A SPOPL/Cullin-3 ubiquitin ligase complex regulates endocytic trafficking by targeting EPS15 at endosomes

Cullin-3 (CUL3)-based ubiquitin ligases regulate endosome maturation and trafficking of endocytic cargo to lysosomes in mammalian cells. Here, we report that these functions depend on SPOPL, a substrate-specific CUL3 adaptor. We find that SPOPL associates with endosomes and is required for both the formation of multivesicular bodies (MVBs) and the endocytic host cell entry of influenza A virus. In SPOPL-depleted cells, endosomes are enlarged and fail to acquire intraluminal vesicles (ILVs). We identify a critical substrate ubiquitinated by CUL3-SPOPL as EPS15, an endocytic adaptor that also associates with the ESCRT-0 complex members HRS and STAM on endosomes. Indeed, EPS15 is ubiquitinated in a SPOPL-dependent manner, and accumulates with HRS in cells lacking SPOPL. Together, our data indicates that a CUL3-SPOPL E3 ubiquitin ligase complex regulates endocytic trafficking and MVB formation by ubiquitinating and degrading EPS15 at endosomes, thereby influencing influenza A virus infection as well as degradation of EGFR and other EPS15 targets.

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Author response: A SPOPL/Cullin-3 ubiquitin ligase complex regulates endocytic trafficking by targeting EPS15 at endosomes

10.7554/elife.13841.018 ◽

2016 ◽

Author(s):

Michaela Gschweitl ◽

Anna Ulbricht ◽

Christopher A Barnes ◽

Radoslav I Enchev ◽

Ingrid Stoffel-Studer ◽

...

Keyword(s):

Ubiquitin Ligase ◽

Author Response ◽

Endocytic Trafficking ◽

Ubiquitin Ligase Complex ◽

Cullin 3

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Abstract A14: DNA alterations to the Cullin-3/Ring box protein-1 E3 ubiquitin ligase complex represent a novel mechanism of NF-κB activation in lung cancer

10.1158/1940-6207.prev-10-a14 ◽

2010 ◽

Author(s):

Larissa Pikor ◽

Kelsie L. Thu ◽

William W. Lockwood ◽

Raj Chari ◽

Ian M. Wilson ◽

...

Keyword(s):

Lung Cancer ◽

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Ubiquitin Ligase Complex ◽

Cullin 3 ◽

Dna Alterations

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Revisiting the NaCl cotransporter regulation by with-no-lysine kinases

AJP Cell Physiology ◽

10.1152/ajpcell.00065.2015 ◽

2015 ◽

Vol 308 (10) ◽

pp. C779-C791 ◽

Cited By ~ 31

Author(s):

Silvana Bazúa-Valenti ◽

Gerardo Gamba

Keyword(s):

Ubiquitin Ligase ◽

E3 Ubiquitin Ligase ◽

Type Ii ◽

Complex Issue ◽

Dark Ages ◽

Ubiquitin Ligase Complex ◽

Pseudohypoaldosteronism Type Ii ◽

Cullin 3 ◽

Increased Activity ◽

Pseudohypoaldosteronism Type

The renal thiazide-sensitive Na+-Cl− cotransporter (NCC) is the salt transporter in the distal convoluted tubule. Its activity is fundamental for defining blood pressure levels. Decreased NCC activity is associated with salt-remediable arterial hypotension with hypokalemia (Gitelman disease), while increased activity results in salt-sensitive arterial hypertension with hyperkalemia (pseudohypoaldosteronism type II; PHAII). The discovery of four different genes causing PHAII revealed a complex multiprotein system that regulates the activity of NCC. Two genes encode for with-no-lysine (K) kinases WNK1 and WNK4, while two encode for kelch-like 3 (KLHL3) and cullin 3 (CUL3) proteins that form a RING type E3 ubiquitin ligase complex. Extensive research has shown that WNK1 and WNK4 are the targets for the KLHL3-CUL3 complex and that WNKs modulate the activity of NCC by means of intermediary Ste20-type kinases known as SPAK or OSR1. The understanding of the effect of WNKs on NCC is a complex issue, but recent evidence discussed in this review suggests that we could be reaching the end of the dark ages regarding this matter.

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Cross-species analysis of LZTR1 loss-of-function mutants demonstrates dependency to RIT1 orthologs

10.1101/2022.01.04.474894 ◽

2022 ◽

Author(s):

Antonio Cuevas-Navarro ◽

Laura Rodriguez-Muñoz ◽

Joaquim Grego-Bessa ◽

Alice Cheng ◽

Katherine A Rauen ◽

...

Keyword(s):

Ubiquitin Ligase ◽

Null Allele ◽

E3 Ubiquitin Ligase ◽

Adaptor Protein ◽

Loss Of Function ◽

Ras Gtpases ◽

Ubiquitin Ligase Complex ◽

Species Analysis ◽

Cullin 3 ◽

Ring E3

RAS GTPases are highly conserved proteins involved in the regulation of mitogenic signaling. We have previously described a novel Cullin 3 RING E3 ubiquitin ligase complex formed by the substrate adaptor protein LZTR1 that binds, ubiquitinates, and promotes proteasomal degradation of the RAS GTPase RIT1. In addition, others have described that this complex is also responsible for the ubiquitination of canonical RAS GTPases. Here, we have analyzed the phenotypes of LZTR1 loss-of-function mutants in both fruit flies and mice and have demonstrated biochemical dependency on their RIT1 orthologs. Moreover, we show that LZTR1 is haplosufficient in mice and that embryonic lethality of the homozygous null allele can be rescued by deletion of RIT1.

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BCL6 Interacts with Cullin-3 Ubiquitin Ligase Complex In B Cells

Blood ◽

10.1182/blood.v116.21.3129.3129 ◽

2010 ◽

Vol 116 (21) ◽

pp. 3129-3129

Author(s):

Ryan T Phan ◽

DanVy Nguyen ◽

Phillipp Nham ◽

Riccardo Dalla-Favera

Keyword(s):

B Cells ◽

B Cell ◽

Ubiquitin Ligase ◽

Transcriptional Repression ◽

Conflicts Of Interest ◽

B Cell Lymphoma ◽

Receptor Activation ◽

Specific Substrate ◽

Ubiquitin Ligase Complex ◽

Cullin 3

Abstract Abstract 3129 The proto-oncogene BCL6 encodes for a BTB/POZ-zinc finger transcriptional repressor which plays an essential role in germinal center (GC) formation and is implicated in the pathogenesis of B-cell lymphoma. BCL6 is shown to be a critical regulator modulating many important functions in B cells, including activation, differentiation, cell cycle arrest and apoptosis. Tight regulation of BCL6 is, therefore, critical for the control of GC reaction as well as for the phenotype of GC-derived lymphomas. In response to B cell receptor activation or DNA damage induction, BCL6 protein is phosphorylated and subsequently degraded through distinct mechanisms that involve ubiquitination process. Here we report that BCL6 interacts with Cullin-3 (Cul3), major component of a multimeric E3 ubiquitin ligase complex. Consistent with previous reports indicating that BTB/POZ domain proteins interact with Cul3, the BCL6-POZ domain is sufficient for BCL6 interaction with Cul3. Importantly, BCL6 and Cul3 interaction is also readily detected in native B cells. Interestingly, this interaction does not affect BCL6 transcriptional repression activity nor does it affect basal level of BCL6 stability. The pathophysiological consequence of this interaction is investigated, including a possibility that BCL6 functions as a specific substrate adaptor for the Cullin-3 ubiquitin complex. Disclosures: No relevant conflicts of interest to declare.

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Mutations in LZTR1 drive human disease by dysregulating RAS ubiquitination

Science ◽

10.1126/science.aap7607 ◽

2018 ◽

Vol 362 (6419) ◽

pp. 1177-1182 ◽

Cited By ~ 52

Author(s):

M. Steklov ◽

S. Pandolfi ◽

M. F. Baietti ◽

A. Batiuk ◽

P. Carai ◽

...

Keyword(s):

Ubiquitin Ligase ◽

Human Disease ◽

Mammalian Cells ◽

Leucine Zipper ◽

Ras Signaling ◽

Ras Proteins ◽

Ubiquitin Ligase Complex ◽

Cullin 3 ◽

Guanosine Triphosphatase

The leucine zipper–like transcriptional regulator 1 (LZTR1) protein, an adaptor for cullin 3 (CUL3) ubiquitin ligase complex, is implicated in human disease, yet its mechanism of action remains unknown. We found that Lztr1 haploinsufficiency in mice recapitulates Noonan syndrome phenotypes, whereas LZTR1 loss in Schwann cells drives dedifferentiation and proliferation. By trapping LZTR1 complexes from intact mammalian cells, we identified the guanosine triphosphatase RAS as a substrate for the LZTR1-CUL3 complex. Ubiquitome analysis showed that loss of Lztr1 abrogated Ras ubiquitination at lysine-170. LZTR1-mediated ubiquitination inhibited RAS signaling by attenuating its association with the membrane. Disease-associated LZTR1 mutations disrupted either LZTR1-CUL3 complex formation or its interaction with RAS proteins. RAS regulation by LZTR1-mediated ubiquitination provides an explanation for the role of LZTR1 in human disease.

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