The Stability of Tropomyosin, a Two-Stranded Coiled-Coil Protein, Is Primarily a Function of the Hydrophobicity of Residues at the Helix-Helix Interface

Biochemistry ◽  
1995 ◽  
Vol 34 (51) ◽  
pp. 16797-16805 ◽  
Author(s):  
Norma J. Greenfield ◽  
Sarah E. Hitchcock-DeGregori
Keyword(s):  
Coiled Coil ◽  
The Stability

scholarly journals Phosphoregulation of tropomyosin is crucial for actin cable turnover and division site placement

2019 ◽  
Vol 218 (11) ◽  
pp. 3548-3559 ◽  
Author(s):  
Saravanan Palani ◽  
Darius V. Köster ◽  
Tomoyuki Hatano ◽  
Anton Kamnev ◽  
Taishi Kanamaru ◽  
...  
Keyword(s):  
Fission Yeast ◽  
Actin Filaments ◽  
Coiled Coil ◽  
Actin Binding ◽  
Division Site ◽  
Actin Cable ◽  
Nonmuscle Cells ◽  
The Stability ◽  
Actin Cables

Tropomyosin is a coiled-coil actin binding protein key to the stability of actin filaments. In muscle cells, tropomyosin is subject to calcium regulation, but its regulation in nonmuscle cells is not understood. Here, we provide evidence that the fission yeast tropomyosin, Cdc8, is regulated by phosphorylation of a serine residue. Failure of phosphorylation leads to an increased number and stability of actin cables and causes misplacement of the division site in certain genetic backgrounds. Phosphorylation of Cdc8 weakens its interaction with actin filaments. Furthermore, we show through in vitro reconstitution that phosphorylation-mediated release of Cdc8 from actin filaments facilitates access of the actin-severing protein Adf1 and subsequent filament disassembly. These studies establish that phosphorylation may be a key mode of regulation of nonmuscle tropomyosins, which in fission yeast controls actin filament stability and division site placement.

scholarly journals Coiled-Coil Trigger Motifs in the 1B and 2B Rod Domain Segments Are Required for the Stability of Keratin Intermediate Filaments

2000 ◽  
Vol 11 (10) ◽  
pp. 3539-3558 ◽  
Author(s):  
Kenneth C. Wu ◽  
Janine T. Bryan ◽  
Maria I. Morasso ◽  
Shyh-Ing Jang ◽  
Jeung-Hoon Lee ◽  
...  
Keyword(s):  
Coiled Coil ◽  
Coiled Coils ◽  
Detectable Effect ◽  
Keratin 5 ◽  
Molecular Stability ◽  
Potential Trigger ◽  
Helical Proteins ◽  
The Stability

Many α-helical proteins that form two-chain coiled coils possess a 13-residue trigger motif that seems to be required for the stability of the coiled coil. However, as currently defined, the motif is absent from intermediate filament (IF) protein chains, which nevertheless form segmented two-chain coiled coils. In the present work, we have searched for and identified two regions in IF chains that are essential for the stability necessary for the formation of coiled-coil molecules and thus may function as trigger motifs. We made a series of point substitutions with the keratin 5/keratin 14 IF system. Combinations of the wild-type and mutant chains were assembled in vitro and in vivo, and the stabilities of two-chain (one-molecule) and two-molecule assemblies were examined with use of a urea disassembly assay. Our new data document that there is a region located between residues 100 and 113 of the 2B rod domain segment that is absolutely required for molecular stability and IF assembly. This potential trigger motif differs slightly from the consensus in having an Asp residue at position 4 (instead of a Glu) and a Thr residue at position 9 (instead of a charged residue), but there is an absolute requirement for a Glu residue at position 6. Because these 13 residues are highly conserved, it seems possible that this motif functions in all IF chains. Likewise, by testing keratin IF with substitutions in both chains, we identified a second potential trigger motif between residues 79 and 91 of the 1B rod domain segment, which may also be conserved in all IF chains. However, we were unable to find a trigger motif in the 1A rod domain segment. In addition, many other point substitutions had little detectable effect on IF assembly, except for the conserved Lys-23 residue of the 2B rod domain segment. Cross-linking and modeling studies revealed that Lys-23 may lie very close to Glu-106 when two molecules are aligned in the A22 mode. Thus, the Glu-106 residue may have a dual role in IF structure: it may participate in trigger formation to afford special stability to the two-chain coiled-coil molecule, and it may participate in stabilization of the two-molecule hierarchical stage of IF structure.

scholarly journals Nanoscale spatial dependence of avidity in an IgG1 antibody

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Agnieszka Jendroszek ◽  
Magnus Kjaergaard
Keyword(s):  
Spatial Dependence ◽  
Target Recognition ◽  
Coiled Coil ◽  
Coiled Coils ◽  
Antibody Engineering ◽  
Bispecific Antibodies ◽  
Secreted Proteins ◽  
Biophysical Techniques ◽  
The Stability ◽  
20 Nm

AbstractAntibodies are secreted proteins that are crucial to recognition of pathogens by the immune system and are also efficient pharmaceuticals. The affinity and specificity of target recognition can increase remarkably through avidity effects, when the antibody can bind a multivalent antigen through more than one epitope simultaneously. A key goal of antibody engineering is thus to optimize avidity, but little is known about the nanoscale spatial dependence of avidity in antibodies. Here, we develop a set of anti-parallel coiled-coils spanning from 7 to 20 nm and validate their structure using biophysical techniques. We use the coiled-coils to control the spacing between two epitopes, and measure how antigen spacing affects the stability of the bivalent antibody:antigen complex. We find a maximal avidity enhancement at a spacing of 13 nm. In contrast to recent studies, we find the avidity to be relatively insensitive to epitope spacing near the avidity maximum as long as it is within the spatial tolerance of the antibody. We thus only see a ~ twofold variation of avidity in the range from 7 to 20 nm. The coiled-coil systems developed here may prove a useful protein nanocaliper for profiling the spatial tolerance and avidity profile of bispecific antibodies.

scholarly journals Metabolic enzyme clustering by coiled coils improves the biosynthesis of resveratrol and mevalonate

2020 ◽  
Author(s):  
Tina Fink ◽  
Bojana Stevović ◽  
René Verwaal ◽  
Johannes A. Roubos ◽  
Rok Gaber ◽  
...  
Keyword(s):  
Spatial Organization ◽  
Noncovalent Interactions ◽  
Coiled Coil ◽  
Product Yield ◽  
Coiled Coils ◽  
Metabolic Enzyme ◽  
Biosynthetic Enzymes ◽  
Reaction Products ◽  
Interaction Domains ◽  
The Stability

Abstract The clustering of biosynthetic enzymes is used in nature to channel reaction products and increase the yield of compounds produced by multiple reaction steps. The coupling of multiple enzymes has been shown to increase the biosynthetic product yield. Different clustering strategies have particular advantages as the spatial organization of multiple enzymes creates biocatalytic cascades with a higher efficiency of biochemical reaction. However, there are also some drawbacks, such as misfolding and the variable stability of interaction domains, which may differ between particular biosynthetic reactions and the host organism. Here, we compared different protein-based clustering strategies, including direct fusion, fusion mediated by intein, and noncovalent interactions mediated through small coiled-coil dimer-forming domains. The clustering of enzymes through orthogonally designed coiled-coil interaction domains increased the production of resveratrol in Escherichia coli more than the intein-mediated fusion of biosynthetic enzymes. The improvement of resveratrol production correlated with the stability of the coiled-coil dimers. The coiled-coil fusion-based approach also increased mevalonate production in Saccharomyces cerevisiae , thus demonstrating the wider applicability of this strategy.

scholarly journals Loss of TRIM31 promotes breast cancer progression through regulating K48- and K63-linked ubiquitination of p53

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Yafei Guo ◽  
Qin Li ◽  
Gang Zhao ◽  
Jie Zhang ◽  
Hang Yuan ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Coiled Coil ◽  
Breast Cancer Progression ◽  
Migration And Invasion ◽  
Breast Cancer Patients ◽  
Loss Of Function ◽  
The Stability

AbstractBreast cancer is the most common cancer in the world. Relapse and metastasis are important factors endangering the life of breast cancer patients, but the mechanism is still unclear. The stabilization of p53 is essential for preventing carcinogenesis, and ubiquitination is one of the main ways to regulate the stability of p53. Tripartite motif-containing 31 (TRIM31) is a new member of the TRIM family and functions as an E3 ubiquitin ligase. It acts as a cancer promoter or suppressor in the malignant processes of multiple cancers. However, the function of TRIM31 in breast cancer progression remains unknown. In this study, we showed that TRIM31 is downregulated in breast cancer tissues and negatively correlated with breast cancer progression. Both gain- and loss-of-function assays indicated that TRIM31 inhibits the proliferation, colony formation, migration, and invasion of breast cancer cells. Further investigation demonstrated that TRIM31 directly interacts with p53, and inducing the K63-linked ubiquitination of p53 via its RING domain, Meanwhile, TRIM31 suppresses the MDM2-mediated K48-linked ubiquitination of p53 through competitive inhibiting the interaction of MDM2 and p53, leading to the p53 stabilization and activation. Knockdown of p53 reversed the inhibitory effects of TRIM31 on the growth and metastasis of breast cancer cells. Moreover, we found that the RING and coiled-coil (C–C) domains of TRIM31 were essential for its tumor suppressor function. Taken together, our findings reveal a novel mechanism by which TRIM31 suppresses breast cancer development through the stabilization and activation of p53 and define a promising therapeutic strategy for restoring TRIM31 to treat breast cancer.

Effect of helix length on the stability of the lac repressor antiparallel coiled coil

Biopolymers ◽  
2015 ◽  
Vol 104 (4) ◽  
pp. 395-404 ◽  
Author(s):  
Wheaton Little ◽  
James P. Robblee ◽  
Caroline L. Dahlberg ◽  
Bashkim Kokona ◽  
Robert Fairman
Keyword(s):  
Coiled Coil ◽  
Lac Repressor ◽  
The Stability ◽  
Antiparallel Coiled Coil

scholarly journals Structure of a truncated form of leucine zipper II of JIP3 reveals an unexpected antiparallel coiled-coil arrangement

2016 ◽  
Vol 72 (3) ◽  
pp. 198-206 ◽  
Author(s):  
Paola Llinas ◽  
Mélanie Chenon ◽  
T. Quyen Nguyen ◽  
Catia Moreira ◽  
Annélie de Régibus ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Molecular Motors ◽  
Map Kinases ◽  
Leucine Zipper ◽  
Coiled Coil ◽  
Structural Rearrangement ◽  
Structural Motif ◽  
Scaffolding Proteins ◽  
Truncated Form ◽  
The Stability

JIP3 and JIP4, two highly related scaffolding proteins for MAP kinases, are binding partners for two molecular motors as well as for the small G protein ARF6. The leucine zipper II (LZII) region of JIP3/4 is the binding site for these three partners. Previously, the crystal structure of ARF6 bound to JIP4 revealed LZII in a parallel coiled-coil arrangement. Here, the crystal structure of an N-terminally truncated form of LZII of JIP3 alone shows an unexpected antiparallel arrangement. Using molecular dynamics and modelling, the stability of this antiparallel LZII arrangement, as well as its specificity for ARF6, were investigated. This study highlights that N-terminal truncation of LZII can change its coiled-coil orientation without affecting its overall stability. Further, a conserved buried asparagine residue was pinpointed as a possible structural determinant for this dramatic structural rearrangement. Thus, LZII of JIP3/4 is a versatile structural motif, modifications of which can impact partner recognition and thus biological function.

Sign in / Sign up

Export Citation Format

Share Document