Single-spanning transmembrane domains in cell growth and cell-cell interactions

Hubert, P.; Sawma, Paul; Duneau, Jean‐Pierre; Khao, Jonathan; Hénin, Jérôme; Bagnard, Dominique; Sturgis, James N.

doi:10.4161/cam.4.2.12430

Cited by 80 publications

(63 citation statements)

References 180 publications

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“…M embrane proteins that span the lipid bilayer once constitute around 50% of all integral membrane proteins (1). Although monospanning membrane proteins carry out numerous key biological functions, including environmental sensing, organellespecific catalysis, and the regulation of cell morphology, only individual domains or subdomains are currently represented in the Protein Data Bank, and structural information about interactions between their transmembrane domains and extramembranous components is lacking.…”

mentioning

confidence: 99%

Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer

Monk

Tomasiak

Keniya

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

248

283

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Bitopic integral membrane proteins with a single transmembrane helix play diverse roles in catalysis, cell signaling, and morphogenesis. Complete monospanning protein structures are needed to show how interaction between the transmembrane helix and catalytic domain might influence association with the membrane and function. We report crystal structures of full-length Saccharomyces cerevisiae lanosterol 14α-demethylase, a membrane monospanning cytochrome P450 of the CYP51 family that catalyzes the first postcyclization step in ergosterol biosynthesis and is inhibited by triazole drugs. The structures reveal a well-ordered N-terminal amphipathic helix preceding a putative transmembrane helix that would constrain the catalytic domain orientation to lie partly in the lipid bilayer. The structures locate the substrate lanosterol, identify putative substrate and product channels, and reveal constrained interactions with triazole antifungal drugs that are important for drug design and understanding drug resistance.M embrane proteins that span the lipid bilayer once constitute around 50% of all integral membrane proteins (1). Although monospanning membrane proteins carry out numerous key biological functions, including environmental sensing, organellespecific catalysis, and the regulation of cell morphology, only individual domains or subdomains are currently represented in the Protein Data Bank, and structural information about interactions between their transmembrane domains and extramembranous components is lacking. Cytochrome P450 proteins are prominent enzymes with orthologs found in all kingdoms of life. In eukaryotes, microsomal members of this major family of mixed-function mono-oxygenases contain a single transmembrane helix and can be grouped in two broad functional categories: biodefense, such as the first phase of xenobiotic detoxification, and core metabolism including reactions in sterol biosynthesis and fatty acid oxidation (2).The lanosterol 14α-demethylases or CYP51 enzymes, probably the most genetically ancient of the cytochrome P450 families, play a central role in cholesterol or ergosterol biosynthesis (3). CYP51s carry out three consecutive mono-oxygenase reaction cycles to remove the 14α-methyl group from lanosterol to yield 4,4-dimethyl-cholesta-8,14,24-trienol, a key precursor in cholesterol and ergosterol biosynthesis, releasing water and formic acid (3). Because of the key roles that CYP51s play in yeast, filamentous fungi, and some parasitic protozoa, these enzymes are therapeutic targets for antimicrobial agents, including fluconazole (FLC), voriconazole (VCZ), and itraconazole (ITC) (4). Fungal infections play an increasingly significant role in disease, impacting agriculture ecosystems and human health, especially in immunocompromised individuals (5-7) for whom antifungal resistance continually poses a threat (8). In humans CYP51 is being tested as a target for cholesterol-lowering drugs (9) and in antiangiogenic cancer therapies (10). A limited set of cytochrome P450 isoforms (1A2, 2C8, 2C...

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mentioning

confidence: 99%

Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer

Monk

Tomasiak

Keniya

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

248

283

View full text Add to dashboard Cite

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“…The presence of motifs and characteristics known to be involved in TMD interactions does not necessarily mean that they actually facilitate an interaction due to the unpredictable influence of the surrounding sequence context (15)(16)(17). In terms of the neuraminidase TMDs from IAVs, the initial TMD sequence analysis gave no indication of a conserved interaction motif as GXXXG, QXXS, periodic Ile/Leu/Val motifs, and the polar residues Asn, Gln, and Ser were all found.…”

Section: Discussionmentioning

confidence: 98%

“…However, these motifs are dependent on their surrounding sequence and local environment in unpredictable manners, indicating that our understanding of how TMDs associate with specificity in limited sequence space remains rudimentary (8,12,(15)(16)(17).…”

mentioning

confidence: 99%

Polar Residues and Their Positional Context Dictate the Transmembrane Domain Interactions of Influenza A Neuraminidases

Nordholm

Silva

Damjanovic

et al. 2013

Journal of Biological Chemistry

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Background: Transmembrane domain (TMD) interactions in bitopic proteins are less understood than in multispanning proteins. Results:The interaction of the neuraminidase TMDs from influenza A viruses increases with decreasing hydrophobicity. Conclusion: Neuraminidase TMD interactions are dependent on the helix localization and positioning of their polar residues in the membrane bilayer. Significance: Polar-mediated TMD interactions are related to their membrane-integration properties.

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“…Membrane proteins constitute 25-30% of all proteins identified in sequenced genomes, and understanding their functions is important, because they represent the majority of current drug targets (1). Conventionally, function is inferred from structural studies of membrane proteins; these studies involve expression and purification of natural or recombinant membrane proteins followed by crystallization.…”

mentioning

confidence: 99%

“…ssMPs contain a single transmembrane (TM) helix that anchors the hydrophilic ectodomains on the membrane surface; ssMPs represent approximately one-half of all membrane proteins and are involved in important cellular functions, such as cell-cell communication and cell adhesion (1). We synthesize ssMPs in a reconstituted cell-free protein synthesis system in the presence of oil drops (8,9).…”

mentioning

confidence: 99%

One-pot system for synthesis, assembly, and display of functional single-span membrane proteins on oil–water interfaces

Yunker

Asahara

Hung

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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Single-span membrane proteins (ssMPs) represent approximately one-half of all membrane proteins and play important roles in cellular communications. However, like all membrane proteins, ssMPs are prone to misfolding and aggregation because of the hydrophobicity of transmembrane helices, making them difficult to study using common aqueous solution-based approaches. Detergents and membrane mimetics can solubilize membrane proteins but do not always result in proper folding and functionality. Here, we use cell-free protein synthesis in the presence of oil drops to create a one-pot system for the synthesis, assembly, and display of functional ssMPs. Our studies suggest that oil drops prevent aggregation of some in vitro-synthesized ssMPs by allowing these ssMPs to localize on oil surfaces. We speculate that oil drops may provide a hydrophobic interior for cotranslational insertion of the transmembrane helices and a fluidic surface for proper assembly and display of the ectodomains. These functionalized oil drop surfaces could mimic cell surfaces and allow ssMPs to interact with cell surface receptors under an environment closest to cell-cell communication. Using this approach, we showed that apoptosis-inducing human transmembrane proteins, FasL and TRAIL, synthesized and displayed on oil drops induce apoptosis of cultured tumor cells. In addition, we take advantage of hydrophobic interactions of transmembrane helices to manipulate the assembly of ssMPs and create artificial clusters on oil drop surfaces. Thus, by coupling protein synthesis with self-assembly at the water-oil interface, we create a platform that can use recombinant ssMPs to communicate with cells.embrane proteins populate the surfaces of cells and allow cells to sense and interact with their external environments. Membrane proteins constitute 25-30% of all proteins identified in sequenced genomes, and understanding their functions is important, because they represent the majority of current drug targets (1). Conventionally, function is inferred from structural studies of membrane proteins; these studies involve expression and purification of natural or recombinant membrane proteins followed by crystallization. However, membrane proteins are notoriously hard to work with because of their hydrophobic domains that can cause misfolding and aggregation (2). Consequently, detergents and membrane mimetics (3) are used to solubilize membrane proteins. To avoid cytotoxicity caused by in vivo expression and enable highthroughput production, cell-free systems are used to express membrane proteins in vitro (4-7). Despite recent progresses, understanding the functions of membrane proteins is still a lengthy and difficult process.Here, we develop a one-pot approach for synthesis, assembly, and display of single-span membrane proteins (ssMPs) for direct functional studies. ssMPs contain a single transmembrane (TM) helix that anchors the hydrophilic ectodomains on the membrane surface; ssMPs represent approximately one-half of all membrane proteins and are involved ...

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Single-spanning transmembrane domains in cell growth and cell-cell interactions

Cited by 80 publications

References 180 publications

Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer

Architecture of a single membrane spanning cytochrome P450 suggests constraints that orient the catalytic domain relative to a bilayer

Polar Residues and Their Positional Context Dictate the Transmembrane Domain Interactions of Influenza A Neuraminidases

One-pot system for synthesis, assembly, and display of functional single-span membrane proteins on oil–water interfaces

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