Cryo-EM structures of the TTYH family reveal a novel architecture for lipid interactions

Sukalskaia, A.; Straub, Monique S; Deneka, Dawid; Sawicka, Marta; Dutzler, Raimund

doi:10.1038/s41467-021-25106-4

Cited by 17 publications

(35 citation statements)

References 61 publications

(87 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the tetrameric stoichiometry we observed in the cellular environment, the recent structures of members of the TTYH family shared a dimeric organization 14 , 15 . However, as these structures were determined following membrane solubilization by detergents, we hypothesized that this process may result in the dissociation of TTYH complexes.…”

Section: Resultscontrasting

confidence: 87%

“…While in situ cross-linking indicated that mTTYH proteins are composed of multiple subunits, we cannot exclude the possibility that heteromeric assembly formation of mTTYH dimers 14 , 15 with additional endogenous proteins underlies the observed migration patterns. Thus, to directly examine the number of mTTYH subunits within a complex in living cells, we resorted to the single-molecule subunit counting approach 22 .…”

Section: Resultsmentioning

confidence: 88%

“…Importantly, two recent studies elucidated the long-sought structure of TTYH family members 14 , 15 . However, strikingly, anion conductive pathways were not identified in any of the human (hTTYH) or mouse (mTTYH) members.…”

Section: Introductionmentioning

confidence: 99%

“…The structures revealed a novel subunit topology common to all TTYH members, consisting of five transmembrane helices and a large α-helical extracellular domain (ECD). hTTYH paralogs and mTTYH3 were shown to exhibit a side-by-side cis -dimeric organization, involving interaction interfaces within the ECD and transmembrane regions 14 , 15 . This is in contrast to the predicted tetrameric organization inferred from electrophysiological studies 9 .…”

Section: Introductionmentioning

confidence: 99%

“…As the structures of TTYH members, determined following detergent-mediated membrane solubilization, revealed distinct spatial organizations 14 , 15 , elucidation of their stoichiometry in the native membrane environment may hint toward their functional and cellular roles. Indeed, the extraction of membrane proteins from their native environment can result in dramatic changes to their ternary and quaternary organizations 21 , hampering the elucidation of TTYH physiological roles.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

TTYH family members form tetrameric complexes at the cell membrane

et al. 2022

View full text Add to dashboard Cite

The conserved Tweety homolog (TTYH) family consists of three paralogs in vertebrates, displaying a ubiquitous expression pattern. Although considered as ion channels for almost two decades, recent structural and functional analyses refuted this role. Intriguingly, while all paralogs shared a dimeric stoichiometry following detergent solubilization, their structures revealed divergence in their relative subunit orientation. Here, we determined the stoichiometry of intact mouse TTYH (mTTYH) complexes in cells. Using cross-linking and single-molecule fluorescence microscopy, we demonstrate that mTTYH1 and mTTYH3 form tetramers at the plasma membrane, stabilized by interactions between their extracellular domains. Using blue-native PAGE, fluorescence-detection size-exclusion chromatography, and hydrogen/deuterium exchange mass spectrometry (HDX-MS), we reveal that detergent solubilization results in tetramers destabilization, leading to their dissolution into dimers. Moreover, HDX-MS demonstrates that the extracellular domains are stabilized in the context of the tetrameric mTTYH complex. Together, our results expose the innate tetrameric organization of TTYH complexes at the cell membrane. Future structural analyses of these assemblies in native membranes are required to illuminate their long-sought cellular function.

show abstract

Section: Resultscontrasting

confidence: 87%

Section: Resultsmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

TTYH family members form tetrameric complexes at the cell membrane

et al. 2022

View full text Add to dashboard Cite

show abstract

Drosophila tweety facilitates autophagy to regulate mitochondrial homeostasis and bioenergetics in Glia

Leung,

Mansour,

Rousseau

et al. 2023

Glia

View full text Add to dashboard Cite

Mitochondria support the energetic demands of the cells. Autophagic turnover of mitochondria serves as a critical pathway for mitochondrial homeostasis. It is unclear how bioenergetics and autophagy are functionally connected. Here, we identify an endolysosomal membrane protein that facilitates autophagy to regulate ATP production in glia. We determined that Drosophila tweety (tty) is highly expressed in glia and localized to endolysosomes. Diminished fusion between autophagosomes and endolysosomes in tty‐deficient glia was rescued by expressing the human Tweety Homolog 1 (TTYH1). Loss of tty in glia attenuated mitochondrial turnover, elevated mitochondrial oxidative stress, and impaired locomotor functions. The cellular and organismal defects were partially reversed by antioxidant treatment. We performed live‐cell imaging of genetically encoded metabolite sensors to determine the impact of tty and autophagy deficiencies on glial bioenergetics. We found that tty‐deficient glia exhibited reduced mitochondrial pyruvate consumption accompanied by a shift toward glycolysis for ATP production. Likewise, genetic inhibition of autophagy in glia resulted in a similar glycolytic shift in bioenergetics. Furthermore, the survival of mutant flies became more sensitive to starvation, underlining the significance of tty in the crosstalk between autophagy and bioenergetics. Together, our findings uncover the role for tty in mitochondrial homeostasis via facilitating autophagy, which determines bioenergetic balance in glia.

show abstract

Tweety homolog 3 promotes colorectal cancer progression through mutual regulation of histone deacetylase 7

Lu,

Deng,

Liu

et al. 2024

MedComm

View full text Add to dashboard Cite

Colorectal cancer (CRC) is one of the leading cancers worldwide, with metastasis being a major cause of high mortality rates among patients. In this study, dysregulated gene Tweety homolog 3 (TTYH3) was identified by Gene Expression Omnibus database. Public databases were used to predict potential competing endogenous RNAs (ceRNAs) for TTYH3. Quantitative real‐time polymerase chain reaction, western blot, and immunohistochemistry were utilized to analyze TTYH3 and histone deacetylase 7 (HDAC7) levels. Luciferase assays confirmed miR‐1271‐5p directly targeting the 3′ untranslated regions of TTYH3 and HDAC7. In vitro experiments such as transwell and human umbilical vein endothelial cell tube formation, as well as in vivo mouse models, were conducted to assess the biological functions of TTYH3 and HDAC7. We discovered that upregulation of TTYH3 in CRC promotes cell migration by affecting the Epithelial–mesenchymal transition pathway, which was independent of its ion channel activity. Mechanistically, TTYH3 and HDAC7 functioned as ceRNAs, reciprocally regulating each other's expression. TTYH3 competes for binding miR‐1271‐5p, increasing HDAC7 expression, facilitating CRC metastasis and angiogenesis. This study reveals the critical role of TTYH3 in promoting CRC metastasis through ceRNA crosstalk, offering new insights into potential therapeutic targets for clinical intervention.

show abstract

Cryo-EM structures of the TTYH family reveal a novel architecture for lipid interactions

Cited by 17 publications

References 61 publications

TTYH family members form tetrameric complexes at the cell membrane

TTYH family members form tetrameric complexes at the cell membrane

Drosophila tweety facilitates autophagy to regulate mitochondrial homeostasis and bioenergetics in Glia

Tweety homolog 3 promotes colorectal cancer progression through mutual regulation of histone deacetylase 7

Contact Info

Product

Resources

About