H, N and C resonance assignments of eggcase silk protein 3.

Spider silk is a high-performance biomaterial known for its outstanding combination of strength and flexibility. Among the six distinct types of spider silk, eggcase silk stands out as it is exclusively produced from the tubuliform gland, playing a specialized role in offspring protection. In the spider species Latrodectus hesperus, eggcase silk is spun from a large spidroin complex, including the major silk component tubuliform spidroin 1 (TuSp1) and at least six different minor silk components.

The solution structure of human leptin reveals a conformational plasticity important for receptor recognition.

Leptin is a multi-potency cytokine that regulates various physiological functions, including weight control and energy homeostasis. Signaling of leptin is also important in many aging-related diseases. Leptin is required for the noncovalent crosslinking of different extracellular domains of leptin receptors, which is critical for receptor activation and downstream signaling.

Chemical shift assignments of wildtype human leptin.

Leptin is an adipose tissue-expressed 16-kDa hormone encoded by the ob/ob gene. It serves a crucial role in regulating diverse physiological processes, including body weight control, energy homeostasis regulation, promotion of cell proliferation, and more. Emerging research has also revealed potential implications of leptin in various aging-related diseases, suggesting multifaceted physiological roles of leptin.

Equilibrium between monomers and dimers of the death domain of the p75 neurotrophin receptor in solution.

p75 neurotrophin receptor (p75) contains a C-terminal globular protein module known as the death domain (DD), which plays a central role in apoptotic and inflammatory signaling through the formation of oligomeric protein complexes. A monomeric state of the p75-DD also exists depending on its chemical environment in vitro. However, studies on the oligomeric states of the p75-DD have produced conflicting findings and sparked great controversy.

Structural insights of the toxin-antitoxin system VPA0770-VPA0769 in Vibrio parahaemolyticus.

Toxin-antitoxin (TA) systems are involved in both normal bacterial physiology and pathogenicity, including gene regulation, antibiotic resistance, and bacteria persistence under stressful environments. In pathogenic Vibrio parahaemolyticus, however, TA interaction and assembly remain largely unknown. In this work, we identified a new RES-Xre type II TA module, encoded by gene cluster vpa0770-vpa0769 on chromosome II of V.

Recent progress in leptin signaling from a structural perspective and its implications for diseases.

As a multi-potency cytokine, leptin not only plays a crucial role in controlling weight and energy homeostasis but also participates in the metabolic balance in the human body. Leptin is a small helical protein with a molecular weight of 16 kDa. It can interact with multiple subtypes of its receptors to initiate intracellular signal transduction and exerts physiological effects.

Toxin-antitoxin systems in pathogenic species: a mini review from a structure perspective.

Toxin-antitoxin (TA) genetic modules have been found to widely exist in bacterial chromosomes and mobile genetic elements. They are composed of stable toxins and less stable antitoxins that can counteract the toxicity of toxins. The interactions between toxins and antitoxins could play critical roles in the virulence and persistence of pathogenic bacteria.

A Structural and Functional Perspective of Death Receptor 6.

As a member of the tumor necrosis factor receptor superfamily (TNFRSF), death receptor 6 (DR6) has a similar structural architecture to other family members. The extracellular region of DR6 contains four cysteine-rich domains, followed by a single-pass transmembrane domain and an intracellular region. Since its discovery, DR6 has become an orphan receptor ubiquitously expressed to transduce unique signaling pathways.

Critical role of minor eggcase silk component in promoting spidroin chain alignment and strong fiber formation.

Natural spider silk with extraordinary mechanical properties is typically spun from more than one type of spidroin. Although the main components of various spider silks have been widely studied, little is known about the molecular role of the minor silk components in spidroin self-assembly and fiber formation. Here, we show that the minor component of spider eggcase silk, TuSp2, not only accelerates self-assembly but remarkably promotes molecular chain alignment of spidroins upon physical shearing.

H, N and C resonance assignments of a repetitive domain of tubuliform spidroin 2.

Spider silk is renowned for its excellent mechanical properties. Among six types of silk and one silk glue produced by different abdominal glands for various purposes, tubuliform (eggcase) silk is unique due to its high serine and low glycine content. Eggcase silk is spun from at least two spidroins, tubuliform spidroin 1 (TuSp1) and TuSp2.

Structural basis of NF-κB signaling by the p75 neurotrophin receptor interaction with adaptor protein TRADD through their respective death domains.

The p75 neurotrophin receptor (p75) is a critical mediator of neuronal death and tissue remodeling and has been implicated in various neurodegenerative diseases and cancers. The death domain (DD) of p75 is an intracellular signaling hub and has been shown to interact with diverse adaptor proteins. In breast cancer cells, binding of the adaptor protein TRADD to p75 depends on nerve growth factor and promotes cell survival.

[Formation of natural silk and progress in artificial spinning].

Natural silks, produced by spiders and silkworms, are excellent materials with marvelous mechanical properties, biocompatibility and biodegradability, and widely used in the fields of textile, optics, electronics, biomedicine and environmental engineering. So far, there are many spinning methods to improve the mechanical properties of artificial fibers, such as wet spinning, dry spinning, and electrospinning. However, the performance of most artificial fibers is still inferior to natural silks.

Functional roles in cell signaling of adaptor protein TRADD from a structural perspective.

TRADD participates in various receptor signaling pathways and plays vital roles in many biological activities, including cell survival and apoptosis, in different cellular contexts. TRADD has two distinct functional domains, a TRAF-binding domain at the N-terminus and a death domain (DD) at the C-terminus. The TRAF binding domain of TRADD folds into an α-β plait topology and is mainly responsible for binding TRAF2, while the TRADD-DD can interact with a variety of DD-containing proteins, including receptors and intracellular signaling molecules.

Self-assembly of tubuliform spidroins driven by hydrophobic interactions among terminal domains.

Spider silk has remarkable physical and biocompatible properties. Investigation of structure-function relationship and self-assembly process of spidroins is necessary for uncovering the mechanism of silk fiber formation. Nevertheless, how the terminal domains initiate self-assembly of soluble tubuliform spidroins to form solid eggcase silk is still not fully understood.

Characterization and analysis of a novel diguanylate cyclase PA0847 from PAO1.

As a central signaling molecule, cyclic diguanylate (c-di-GMP) is found to regulate various bacterial phenotypes, especially those involved in pathogen infection and drug resistance. Noticeably, many microbes have up to dozens of proteins that are involved in c-di-GMP metabolism. This apparent redundancy and the relevant functional specificity have become the focus of research.

Death domain of p75 neurotrophin receptor: a structural perspective on an intracellular signalling hub.

The death domain (DD) is a globular protein motif with a signature feature of an all-helical Greek-key motif. It is a primary mediator of a variety of biological activities, including apoptosis, cell survival and cytoskeletal changes, which are related to many neurodegenerative diseases, neurotrauma, and cancers. DDs exist in a wide range of signalling proteins including p75 neurotrophin receptor (p75 ), a member of the tumour necrosis factor receptor superfamily.

From EST to novel spider silk gene identification for production of spidroin-based biomaterials.

A cDNA library from a pool of all the seven silk glands from a tropical spider species was constructed. More than 1000 expressed sequence tag (EST) clones were created. Almost 65% of the EST clones were identified and around 50% were annotated.

H, N and C chemical shift assignments of the C-terminal domain of TRADD.

The tumor necrosis factor receptor-associated death domain protein, TRADD, is a multifunctional intracellular molecule participating in divergent signaling pathways, such as NF-κB and apoptosis. TRADD consists of two structurally distinct domains. Its N-terminal domain displays an α-β plaits fold while its C-terminal domain belongs to the death domain (DD) superfamily.

Structure of the C-terminal domain of TRADD reveals a novel fold in the death domain superfamily.

The TNFR1-associated death domain protein (TRADD) is an intracellular adaptor protein involved in various signaling pathways, such as antiapoptosis. Its C-terminal death domain (DD) is responsible for binding other DD-containing proteins including the p75 neurotrophin receptor (p75). Here we present a solution structure of TRADD DD derived from high-resolution NMR spectroscopy.

APOBEC3DE Inhibits LINE-1 Retrotransposition by Interacting with ORF1p and Influencing LINE Reverse Transcriptase Activity.

Human long interspersed elements 1 (LINE-1 or L1) is the only autonomous non-LTR retroelement in humans and has been associated with genome instability, inherited genetic diseases, and the development of cancer. Certain human APOBEC3 family proteins are known to have LINE-1 restriction activity. The mechanisms by which APOBEC3 affects LINE-1 retrotransposition are not all well characterized; here, we confirm that both A3B and A3DE have a strong ability to inhibit LINE-1 retrotransposition.

[The different contraction between rat gastric longitudinal and circular smooth muscle induced by extracellular nucleotides].

Objective: To test the different contrctile responses of extracellular nucleotides, such as ATP, UTP and nucleotide uridine adenosine tetraphosphate (Up4A) in gastric longitudinal muscle (LM) and circular muscle (CM). Examined the effect of P2X and P2Y receptor antagonists (in this study, we used IP5I and suramin) and cyclooxygenase inhibitor (indomethacin) on Up4A induced contractile responses in LM and CM.

Methods: The rats were sacrificed and the stomachs were opened to gain LM and CM.

Uridine adenosine tetraphosphate induces contraction of circular and longitudinal gastric smooth muscle by distinct signaling pathways.

Extracellular nucleotides uridine-5'-triphosphate (UTP) and adenosine-5'-triphosphate (ATP) induce contraction of gastric smooth muscle (SM). The dinucleotide uridine adenosine tetraphosphate (Up4 A), an endothelium-derived contraction factor, induces vascular SM contraction. Its effect on gastric SM contractions, however, is unknown.

Estrogen metabolite 2-methoxyestradiol prevents hypertension in deoxycorticosterone acetate-salt rats.

Purpose: Our early work showed that the estrogen metabolite 2-methoxyestradiol (2ME) inhibits proliferation of vascular smooth muscle cells (SMCs) and vascular contractility through an endothelium-dependent mechanism. The aim of this study was to examine whether 2ME prevents the development of hypertension in rats.

Methods: A hypertensive model was established in uninephrectomized rats using deoxycorticosterone acetate (DOCA)-salt.