DENND2B activates Rab35 at the intercellular bridge, regulating cytokinetic abscission and tetraploidy

Kumar, Rahul; Francis, Vincent; Ioannou, Maria S.; Aguila, Adriana; Khan, Maleeha; Banks, Emily; Kulasekaran, Gopinath; McPherson, Peter S.

doi:10.1016/j.celrep.2023.112795

“…Our screening revealed 20 DENND6A/Rab pairs: Rab3B, Rab3C, Rab3D, Rab4A, Rab4B, Rab8A, Rab8B, Rab11A, Rab11B, Rab14, Rab19, Rab22A, Rab22B, Rab25, Rab27A, Rab30, Rab32, Rab34, Rab39A, and Rab43. While the large number of Rabs translocated to the mitochondria was somewhat surprising, it is now evident that DENN domain proteins possess a broader target spectrum than previously appreciated 72 , 73 , which could explain the relative scarcity of GEFs compared to the total number of Rab GTPases 28 . Moreover, it is also possible that among the identified pairs, some may serve as GEF substrates while others act as binding partners but not as substrates.…”

Section: Resultsmentioning

confidence: 97%

“…We conducted a comprehensive screening of DENND6A against all 60 Rab GTPases using a cell-based assay that involves DENN domain-mediated recruitment of Rabs to mitochondrial membranes (Fig. 4a ) 72 , 73 . Our assay is based on the finding that GEFs play a primary role in driving the spatial and temporal localization of Rab GTPases 74 .…”

Section: Resultsmentioning

confidence: 99%

DENND6A links Arl8b to a Rab34/RILP/dynein complex, regulating lysosomal positioning and autophagy

Kumar,

Khan,

Francis

et al. 2024

Nat Commun

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Lysosomes help maintain cellular proteostasis, and defects in lysosomal positioning and function can cause disease, including neurodegenerative disorders. The spatiotemporal distribution of lysosomes is regulated by small GTPases including Rabs, which are activated by guanine nucleotide exchange factors (GEFs). DENN domain proteins are the largest family of Rab GEFs. Using a cell-based assay, we screened DENND6A, a member of the DENN domain protein family against all known Rabs and identified it as a potential GEF for 20 Rabs, including Rab34. Here, we demonstrate that DENND6A activates Rab34, which recruits a RILP/dynein complex to lysosomes, promoting lysosome retrograde transport. Further, we identify DENND6A as an effector of Arl8b, a major regulatory GTPase on lysosomes. We demonstrate that Arl8b recruits DENND6A to peripheral lysosomes to activate Rab34 and initiate retrograde transport, regulating nutrient-dependent lysosomal juxtanuclear repositioning. Loss of DENND6A impairs autophagic flux. Our findings support a model whereby Arl8b/DENND6A/Rab34-dependent lysosomal retrograde trafficking controls autophagy.

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“…Our screening revealed 20 DENND6A/Rab pairs: Rab3B, Rab3C, Rab3D, Rab4A, Rab4B, Rab8A, Rab8B, Rab11A, Rab11B, Rab14, Rab19, Rab22A, Rab22B, Rab25, Rab27A, Rab30, Rab32, Rab34, Rab39A, and Rab43. While the large number of Rabs translocated to the mitochondria was somewhat surprising, it is now evident that DENN domain proteins possess a broader target spectrum than previously appreciated [70] [71], which could explain the relative scarcity of GEFs compared to the total number of Rab GTPases [28]. Moreover, it is also possible that among the identified pairs, some may serve as GEF substrates while others act as binding partners.…”

Section: Screening For Potential Substrate(s) Of Dennd6amentioning

confidence: 95%

“…To identify potential substrates in an unbiased manner, we conducted a comprehensive screening of DENND6A against all 60 Rab GTPases using a cellbased assay that involves DENN domain-mediated recruitment of Rabs to mitochondrial membranes (Fig. 4A) [70] [71]. Our assay is based on the finding that GEFs play a primary role in driving the spatial and temporal localization of Rab GTPases [72].…”

Section: Screening For Potential Substrate(s) Of Dennd6amentioning

confidence: 99%

DENND6A couples Arl8b to a Rab34/RILP/dynein complex regulating retrograde lysosomal trafficking and autophagy

McPherson,

Kumar,

Francis

et al. 2023

Preprint

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Lysosomes help maintain cellular proteostasis, and defects in lysosomal positioning and function lead to diseases including neurodegenerative disorders. The spatiotemporal distribution of lysosomes is regulated by small GTPases, including Rabs, which are activated by guanine nucleotide exchange factors (GEFs). DENN domain–bearing proteins are the largest family of Rab GEFs. Using a cell-based assay, we screened the DENN domain protein family member DENND6A for potential GEF activity toward all 60 Rabs and identified 20 potential DENND6A substrates, including Rab34. Here, we demonstrate that DENND6A activates Rab34, which recruits a RILP/dynein complex to the lysosomes, promoting lysosomal retrograde trafficking from the cell periphery to the minus ends of microtubules. Further, we identify DENND6A as an effector of Arl8b, a major regulatory GTPase on lysosomes. Initially known for promoting anterograde transport of lysosomes, Arl8b also facilitates lysosomal retrograde transport. We demonstrate that Arl8b recruits DENND6A to peripheral lysosomes to activate Rab34 and initiate retrograde transport, regulating nutrient-dependent lysosomal juxtanuclear repositioning and loss of DENND6A impairs autophagic flux. Our findings support a model whereby Arl8b/DENND6A/Rab34-dependent lysosomal retrograde trafficking controls autophagy.

show abstract

“…To identify potential substrates in an unbiased manner, we conducted a comprehensive screening of DENND6A against all 60 Rab GTPases using a cellbased assay that involves DENN domain-mediated recruitment of Rabs to mitochondrial membranes (Fig. 4A) [70] [71]. Our assay is based on the finding that GEFs play a primary role in driving the spatial and temporal localization of Rab GTPases [72].…”

Section: Screening For Potential Substrate(s) Of Dennd6amentioning

confidence: 99%

DENND6A couples Arl8b to a Rab34/RILP/dynein complex regulating retrograde lysosomal trafficking and autophagy

Kumar,

Francis,

Khan

et al. 2023

Preprint

Self Cite

0

View full text Add to dashboard Cite

Lysosomes help maintain cellular proteostasis, and defects in lysosomal positioning and function lead to diseases including neurodegenerative disorders. The spatiotemporal distribution of lysosomes is regulated by small GTPases, including Rabs, which are activated by guanine nucleotide exchange factors (GEFs). DENN domain–bearing proteins are the largest family of Rab GEFs. Using a cell-based assay, we screened the DENN domain protein family member DENND6A for potential GEF activity toward all 60 Rabs and identified 20 potential DENND6A substrates, including Rab34. Here, we demonstrate that DENND6A activates Rab34, which recruits a RILP/dynein complex to the lysosomes, promoting lysosomal retrograde trafficking from the cell periphery to the minus ends of microtubules. Further, we identify DENND6A as an effector of Arl8b, a major regulatory GTPase on lysosomes. Initially known for promoting anterograde transport of lysosomes, Arl8b also facilitates lysosomal retrograde transport. We demonstrate that Arl8b recruits DENND6A to peripheral lysosomes to activate Rab34 and initiate retrograde transport, regulating nutrient-dependent lysosomal juxtanuclear repositioning and loss of DENND6A impairs autophagic flux. Our findings support a model whereby Arl8b/DENND6A/Rab34-dependent lysosomal retrograde trafficking controls autophagy.

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DENND2B activates Rab35 at the intercellular bridge, regulating cytokinetic abscission and tetraploidy

Cited by 6 publications

References 66 publications

DENND6A links Arl8b to a Rab34/RILP/dynein complex, regulating lysosomal positioning and autophagy

DENND6A links Arl8b to a Rab34/RILP/dynein complex, regulating lysosomal positioning and autophagy

DENND6A couples Arl8b to a Rab34/RILP/dynein complex regulating retrograde lysosomal trafficking and autophagy

DENND6A couples Arl8b to a Rab34/RILP/dynein complex regulating retrograde lysosomal trafficking and autophagy

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