bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerolysin (Aeromonas hydrophila)
Authors: Buckley J T 
Published: November 2023

Abstract
Aerolysin is secreted as a 52 kDa protoxin by Aeromonas sp. (see van der Goot et al. 1994, for a recent review). The protein appears to be primarily responsible for the patho¬ genicity of A. hydrophila to mice (Chakraborty et al. 1987). The aerA structural genes from a number of differ¬ ent species have been sequenced, and the structure of the protein from A. hydrophila has been solved (Parker et al. 1994). The protein is a dimer in the crystal as well as in solution and each polypeptide chain contains four domains. More than 70 per cent of the molecule is in β-sheet. The protoxin is converted to the active toxin by proteolytic removal of approximately 43 amino acids from the (-terminus (Howard and Buckley 1985; van der Goot et al. 1992). This can be accomplished by proteases secreted by the bacteria, as well as by mammalian proteases such as trypsin, chymotrypsin, and furin.
Anthrax edema factor (Bacillus anthracis)
Authors: Leppla S H 
Published: November 2023

Abstract
Anthrax edema factor (EF, originally designated Factor I) is a calmodulin-dependent adenylyl cyclase (Leppla 1982) which is one of the three proteins of the anthrax toxin complex (Smith et al. 1955; Leppla 1991a; 1995). The EF gene (Escuyer et al. 1988; Mock et al. 1988; Robertson et al. 1988; Tippetts and Robertson 1988) (GenBank accessions M23179 and M24074), located on the large pXO1 plasmid, encodes a precursor of 800 amino acids. Cleavage of the 33-amino acid signal peptide produces the 767 residue mature protein (PIR Protein database accession JS0029) having a mass of 88.8 kDa. The other proteins of the toxin complex are protective antigen (PA, GenBank M22589) and lethal factor (LF, GenBank M29081 and M30210; see separate entry in this book p. 00). None of the three proteins contain cysteine. As shown in Fig. 1, EF enters cells by binding to proteo¬ lytically activated, receptor-bound PA (Klimpel et al. 1992). EF (or LF) is then endocytosed and translocated from endosomes directly to the cytosol of cells, where it produces unregulated high concentrations of cAMP (Leppla 1982; Gordon et al. 1988). Entry of EF and LF is totally dependent on PA. The receptor for PA is unknown, but is present on nearly all types of cells (Escuyer and Collier 1991; Leppla 1991a).
Ribosome-inactivating proteins
Authors: Stirpe F 
Published: November 2023

Abstract
Ribosome-inactivating proteins (RIPs, review by Barbieri et a/. 1993) are a class of proteins present in various tissues of several plants which inactivate mammalian ribosomes and, with less activity and to variable extent, plant, fungal, and bacterial ribosomes. They are enzymes, N-glycosidases, which release adenine from rRNA. They are divided into two groups: type 1, consisting of a single peptide chain, and type 2, in which an A chain with enzymatic activity is linked to a slightly larger B chain with the properties of a galactosyl-specific lectin. The B chain binds to galactosylterminated receptors on the membrane of most animal cells, allowing the molecule to enter the cytoplasm. Thus most type 2 RIPs are potent toxins, ricin being the best known, although recently some nontoxic lectins with the structure of type 2 RIPs have been described. Type 1 RIPs do not enter easily into cells, and consequently are much less toxic than type 2 RIPs.
Enterotoxin A and cytotoxin B (Clostridium difficile)
Authors: Eichel-Streiber C Von 
Published: November 2023

Abstract
The enterotoxin A (TcdA) and the cytotoxin B (TcdB) of Clostridium difficile are the two virulence factors respons¬ ible for the induction of antibiotical associated diarrhea (AAD) or pseudomembranous colitis (PMC) (Lyerley et al. 1988; Knoop et al. 1993). Diagnosis of the disease is done by identifying the toxins in stool specimens.The high molecular weight cytotoxins are secreted by the bacterium into its culture supernatants from which they may be isolated. One high producer (Sullivan et al. 1982), C. difficile VPl10463 (see Table 1), is used in many laboratories.
IcsA (Shigella flexneri)
Authors: Egile C , Sansonetti P J 
Published: November 2023

Abstract
Shigella flexneri, the causative agent of bacillary dysentery, is a facultative intracellular pathogen that can enter and spread inside the host epithelial cells. This invasion process involves a sequence of molecular interactions between bacterial virulence factors and the host cell cytoskeleton (Sansonetti et al. 1994).
Pyrogenic exotoxins (superantigens) (Staphylococcus aureus and Streptococcus pyogenes)
Authors: Fleischer B 
Published: November 2023

Abstract
The members of the pyrogenic exotoxin family are listed in Table 1 (reviewed in Fleischer 1995). The staphylococcal enterotoxins SEA to SEE have been divided into serotypes by antisera, there are three subtypes of SEC (SEC1, SEC2 and SEC3). Recently, SEG and SEH have been cloned. Sequencing of genes of different isolates has shown a marked microheterogeneity due to mutations. Other members of the family are the streptococcal toxins SPEA and SPEC (also designated as erythrogenic toxins) and the streptococcal superantigen SSA. These molecules consist of a single chain of approximately 230 AA, with one central disulphide bond, they have more or less extensive homologies within the family (Betley et al. 1992). Many of them are encoded on mobile genetic elements. The structure of TSST-1 (originally designated SEF) differs, it has 194 AA and no cysteins. It has only a very low homology to the other toxins but its 3D-structure is very similar (Kim et al. 1994).
Introduction
Authors: Montecucco C , Rappuoli R 
Published: November 2023

Abstract
Life of eukaryotic cells is made possible by an intense vesicular membrane traffic, highly organized in terms of space and kinetics. Ligands, ions, fluids, and portions of the plasma membrane are continuously taken into the cell via endocytosis, and are then addressed to different destinations via sorting compartments. Conversely, proteins, lipids, and glycoconjugates, synthetized in the endoplasmic reticulum and modified in the Golgi apparatus are addressed to their intracellular destination, or are packed inside vesicles for export. Exocytosis can be constitutive for molecules that are to be exported at a basal rate, or regulated for molecules that are to be released in response to appropriate stimuli. The most finely tuned exocytic process is the release of neurotransmitter at the presynaptic membrane. Neurotransmitter is contained within small synaptic vesicles of similar size (about 50 nm in diameter) which are packed at synaptic terminals. The large majority of these vesicles are bound to the cytoskeleton and are not available for immediate release. Some vesicles are bound to the cytosolic face of the presynaptic membrane at active zones which include voltage gated calcium channels. They are ready to release their content in the intersynaptic space. However, at micromolar calcium, only occasionally one of them fuses with the presynaptic membrane, giving rise to a mepp (miniature end plate potential). The membrane depolarization that is at the basis of the transmission of the nerve impulse, opens presynaptic calcium channels. This leads to a local increase of calcium concentration which triggers, within 100-300 µs, the fusion of the synaptic vesicle with the plasma membrane, with the ensuing release of neurotransmitter. The proteins involved in the docking-priming-fusion of small synaptic vesicles with the presynaptic membrane are being characterized.
VAMP-specific botulinum neurotoxins
Authors: Schiavo G 
Published: November 2023

Abstract
Botulinum neurotoxins (BoNT A-G) are the causative agents of the flaccid paralysis of botulism (Hatheway 1995) and are produced by toxigenic strains of Clostridium botulinum and less frequently Cl. barati and Cl. butyricum (Hall et al. 1985; Aureli et al. 1986). BoNTs are produced as a large complex of 300-900 kDa con¬ taining the neurotoxin (150 kDa) and additional components, such as hemagglutinin (300 kDa) and a nontoxic peptide (Sakaguchi 1983). These additional proteins play a role in the stabilization of the neurotoxins to the gut is activated by proteolysis at an exposed loop, generating the active di-chain form of the toxin (DasGupta 1994). This form is composed of the heavy chain (H, 100 kDa) responsible for the interaction of the toxin to specific receptor(s) present at the neuromuscular junction and for the translocation of the light chain (L, 50 kDa) into the cytoplasm. A critical step for the activation of the zinc-endopeptidase activity of the L chain is the reduction of the interchain disulfide bridge (Montecucco and Schiavo 1995).
Introduction
Authors: Pongs O 
Published: November 2023

Abstract
The purpose of this introduction is to outline briefly what some of the peptide toxins may have in common in terms of their structure and function, and to discuss their usefulness as tools in studying K channel function. According to their relatedness in primary sequence, five different peptide-toxin families may be recognized: the apamin family containing members isolated from bee venoms, the charybdotoxin family isolated from scorpion venoms, the dendrotoxin family isolated from snake venoms, the hanatoxins isolated from spider venom, and the sea anemone toxins. It is obvious that the families have been given nonsystematic and sometimes whimsical names which say more about the original discoverers of the peptide toxins than about the molecules themselves. Because of this unsatisfactory situation, C. Miller recently suggested in his excellent review on the structure and function of the charybdotoxin family of K channel¬ blocking peptides a formalized nomenclature (Miller 1995). In analogy to the now widely accepted K channel nomenclature, he proposed to abbreviate K channel¬ blocking peptide toxins as K-toxins (KTx) and in particular the charybdotoxin family members as a-KTxm. n, where m refers to the subfamily and n to the member within the given subfamily. For example, a-KTx1.1 would be charybdotoxin, a-KTx2.1 noxiustoxin etc. as outlined in Table 2 below.
β-Leptinotarsin-h
Authors: Washbourne P 
Published: November 2023

Abstract
β-Leptinotarsin-h is a toxic protein present in the hemolymph of the potato beetle, Leptinotarsa haldemani. The analogous protein, β-leptinotarsin-d, from L. decemlineata, the Colorado potato beetle, is also toxic, but to a lesser extent and so most studies have used the h-type. Purification and SDS-PAGE shows that the proteins have molecular weights of around 57 and 45 kiloDaltons, respectively. Bidimensional PAGE with isoelectric focusing indicate that the protein is slighty acidic (Crosland et al. 1984). Neither the protein nor the gene has been sequenced.Intoxication can only occur when injected; oral ingestion causes no effect, thus it is probable that the protein does not play a defensive role for the potato beetle. Injection of the protein into the thorax of insects causes them to become sluggish, their limbs to become rigid and spread and finally causes death. In vertebrates, symptoms include partial paralysis, decrease in breathing rate, convulsions, and lethargy leading to death (Hsiao and Fraenkel 1969).
Toxin a (‘Naja nigricollis’)
Authors: Ménez A 
Published: November 2023

Abstract
The cobra snakes of the species Naja (Elapidae) produce potent venoms with which they subdue their prey. Among the most toxic components are the curaremimetic toxins which provoke flaccid paralysis and death, as a result of respiratory failure. Detected by Boquet and coworkers (1966), Eaker and Porath showed, in 1967, that toxin a possesses a single chain of 61 amino acids with four disulfides. Toxin a is currently isolated from venom of an African spitting cobra originally named Naja nigricollis (Boquet et al. 1966). Further taxonomical studies suggested that the snake should be named Naja mossambica pa/Iida (Fryklund and Eaker 1975) and more recently Naja pa/Iida (B. Hughes, personal communication). Toxin a was radioactively labelled by replacing a proton of histidine 31 by an atom of tritium, using a procedure based on catalytic deshalogenation (Menez et al. 1971).
Introduction
Authors: Treves S , Zorzato F 
Published: November 2023

Abstract
Ca2+ release from intracellular stores plays an important role in the regulation of numerous cellular functions ranging from muscle contraction to cell division and neurotransmitter release. The intracellular Ca2+ stores of excitable and nonexcitable cells utilize one or two of the intracellular Ca2+ channels to release Ca2+ upon cell stimulation, namely the ryanodine and the inositol 1,4,5-trisphosphate receptors (Berridge 1993).The mammalian ryanodine receptor (RYR) is a large tetrameric oligomer made up of four subunits of 560 kDa, which migrate as a single protein in 5D5- polyacrylamide gel electrophoresis (Pessah et al. 1986; lmagawa et al. 1987; Lai et al. 1988). The purified RYR complex also contains the FK-506 binding protein, a protein of 12 kDa, which is tightly associated to the RYR promoter with a stoichiometric ratio of 1:1 (Jayaraman et al. 1992). Experimental evidence has demonstrated the existence of three distinct isoforms which are preferentially expressed in skeletal muscle, heart, and brain, respectively.
Equinatoxins (Actinia equina L., sea anemone)
Authors: Maček P 
Published: November 2023

Abstract
Equinatoxins I, 11, and Ill (EqTx) are lethal and cytolytic 19 kDa polypeptides (Macek and Lebez 1988) belonging to a larger family of pore-forming toxins from sea anemones (Actiniaria) (see reviews Kem 1988; Turk 1991; Macek 1992). The most abundant isoform, equinatoxin II (synonym: equinatoxin; Ferlan and Lebez 1974), is a single chain, 179 amino acids long, without cysteine (Belmonte et al. 1994). EqTx II is nearly identical to tenebrosin-C from A. tenebrosa (Simpson et al. 1990; Norton et al. 1992) (sequences in Swiss Prot Databank: P17723 TENC_ACTTEX; Genbank: U41661).
Synemin
Authors: Bellin Robert M , Sernett Suzanne W , Robson Richard M 
Published: November 2023

Abstract
Synemin is a very large (230 kDa as judged by SDS-PAGE and 186 kDa by sequencing) intermediate filament (IF) protein that is found with desmin and/or vimentin in embryonic and mature smooth and striated muscle cells, and in a small number of non-muscle cells such as avian erythrocytes and lens. In mature striated muscle cells, synemin is localized with desmin in a collar-like pattern around the periphery of the myofibrillar Z lines where its proposed role is to help desmin IFs link other cytoskeletal structures such as adjacent myofibrils, and the peripheral layer of myofibrils to the sarcolemma.
Filaggrins
Authors: Dale Beverly A , Presland Richard B 
Published: November 2023

Abstract
Filaggrin is named for its ability to cause intermediate filament aggregation in vitro. It is one of the original proteins recognized as an ‘intermediate filament-associated protein’ or IFAP. Filaggrin is expressed by keratinocytes of epidermis and other cornified epithelia as the cells undergo terminal differentiation and form the protective surface layers of the body. It is a cationic protein that is derived from an inactive precursor, profilaggrin, which is insoluble, highly phosphorylated, contains multiple copies of filaggrin, and is processed enzymatically by phosphatases and proteases to the soluble, mature filaggrin.
Lamin-associated proteins
Authors: Gerace Larry , Yang Li 
Published: November 2023

Abstract
Lamin-associated proteins (LAP) comprise a group of polypeptides localized at the inner nuclear membrane which interact stably with nuclear lamins. The three lamin-associated proteins that have been characterized in detail, LAP1, LAP2, and LBR, are all integral membrane proteins, and have potential roles in the attachment of nuclear lamins and/or chromatin to the inner nuclear membrane.1 Another integral membrane protein, emerin, has recently been demonstrated to be a LAP.24
Plectin
Authors: Wiche Gerhard 
Published: November 2023

Abstract
Plectin is a versatile cytoskeletal linker protein of high molecular weight (&gt;500 000 Da) that is abundantly expressed in a wide variety of mammalian tissues and cell types. It interacts with all major cytoskeletal filament networks and is a major constituent of plasma membrane-associated junctional complexes (e.g. hemidesmosomes of epithelia, Z lines, dense plaques and intercalated discs of various types of muscle, and focal contacts). Plectin molecules seem to play an important role in strengthening cells and tissues against mechanical stress, as recently confirmed by findings that link defective plectin expression to human disease (epidermolysis bullosa simplex with muscular dystrophy) and by the observation of similar phenotypes in plectin gene knockout mice. An emerging concept postulates tissue-specific expression of functionally different isoforms of the protein.
Dynein, axonemal
Authors: Gibbons Ian R 
Published: November 2023

Abstract
Axonemal dynein forms a double row of projections, the outer and inner arms, that are attached to the A tubule of each axonemal doublet and extend toward the B tubule of the adjacent doublet.10 The outer dynein arms are distributed along the length of the A tubule, with a constant spacing of 24 nm. The arrangement of inner dynein arms is more complex, with three distinct species of inner arm that are distributed along each A tubule in unevenly spaced triplets.
Dynein, cytoplasmic
Authors: Vallee Richard 
Published: November 2023

Abstract
Cytoplasmic dynein is a large, two-headed ATPase which produces force along microtubules in the retrograde direction (toward the microtubufe minus end). It is involved in a wide range of functions, including retrograde axonal transport and mitosis, and it associates with numerous subcellular structures, including kinetochores and a variety of membrane-bounded organelles.
Myosin, plant
Authors: Kendrick-Jones John , Reichelt Stefanie 
Published: November 2023

Abstract
In plant cells, myosins are believed to play key roles in such prominent actin-based movements as cytoplasmic streaming and directed vesicle transport. Although immunological and biochemical studies have indicated the existence of myosin-like proteins in plants but compared to animal/protozoan myosins little is known about these plant proteins. Recently, 16 plant myosin genes belonging to three unique classes have been cloned and sequenced from various species including Arabidopsis, Helianthus, Acetabularia, and Chlamydomonas.
Auxilin
Authors: Ungewickell Ernst 
Published: November 2023

Abstract
Auxilin is a specialized member of the DnaJ protein family and functions as an essential cofactor to HsclO in the uncoating of clathrin coated vesicles. Auxilin associates preferentially with polymeric clathrin and captures with its carboxyl-terminal J domain the uncoating protein HsclO. Upon ATP hydrolysis, HsclO is transferred to clathrin which dissociates subsequently as a clathrin-HsclO complex from the vesicle membrane. This complex no longer contains auxilin.
Clathrin
Authors: Brodsky Frances M 
Published: November 2023

Abstract
Clathrin is a triskelion-shaped, self-assembling protein which polymerizes into a polyhedral lattice on the cytoplasmic surface of cellular membranes. Formation of the clathrin lattice constitutes a mechanism for sorting membrane-associated proteins which are incorporated into the lattice via bridging proteins, known as adaptors or assembly polypeptides, which interact both with clathrin and transmembrane proteins. Clathrin-coated vesicles are thereby responsible for receptor-mediated endocytosis, for sorting proteins in the trans-Golgi network during lysosome formation, and for membrane sorting during secretory granule maturation.
ERM proteins: ezrin, radixin, and moesin
Authors: Bretscher Anthony , Berryman Mark 
Published: November 2023

Abstract
Ezrin was also known as cytovillin until the identity of the two proteins was appreciated. The N-terminal ∼300 residues show ∼35 per cent identity to the corresponding domain of erythrocyte band 4.1, which defines members of the band 4.1 superfamily. Other members include talin, merlin, and several protein tyrosine phosphatases.
Filamin
Authors: Hock Rick S 
Published: November 2023

Abstract
Filamin, a major component of the microfilament network, plays a critical role in determining the three-dimensional arrangement of actin filaments in vivo and in vitro (reviewed in ref. 1). This actin-cross-linking protein was first isolated from avian smooth muscleand has been purified from many sources including platelets, macrophages, guinea-pig vas deferens, baby hamster kidney (BHK-21) cells, thyroid gland, Hela cells, and motile Dictyostelium amoebae. Filamin is now known to exist in most cell types as a family of isoforms. The number of isoforms has not been defined, although multiple isoforms are apparently present within a single human cell type, Hela cells. Also, isoform switching occurs during myogenesis.
Marcks family
Authors: Aderem Alan 
Published: November 2023

Abstract
MacMARCKS/MRP is the only known MARCKS homologue (see below). However, a number of proteins contain domains that are homologous to the effector domain of MARCKS. These include GAP-43 (neuromodulin), ankyrin, gravin, and diacylglycerol kinase zeta.
p58gas
Authors: Carraway Coralie A Carothers , Carraway Kermit L 
Published: November 2023

Abstract
Binding studies on purified or in vitro translated p58gas are also consistent with this role. It will bind F-actin, but not G-actin.1 Under actin polymerizing conditions p589a9 acts as a capping protein without severing activity. It will bind phospholipid vesicles with little head group specificity, probably due at least in part to fatty acid linked to the N-terminal glycine myristoylation site.
Ponticulin
Authors: Luna Elizabeth J 
Published: November 2023

Abstract
Although an immunologically cross-reactive protein of similar size has been observed in human polymorphonuclear leukocytes, only ponticulin from the soil amoeba, Dictyostelium discoideum, has been characterized. Purified Dictyostelium ponticulin consists of six major 17-kDa isoforms with pis ranging from 4.2 to 5.2 on two-dimensional SDS-PAGE. In addition, minor polypeptides at 19 kDa (five isoforms, p/ range 4.4 to 5.2) and 15 kDa (two isoforms, pl’s 4.3 and 4.7) co-isolate with ponticulin on F-actin affinity columns. Because all these isoforms are absent from cells in which the single-copy gene encoding ponticulin has been disrupted, the ponticulin isoforms appear to arise from differential post-translational processing.
Profilins
Authors: Pollard Thomas D 
Published: November 2023

Abstract
The following provides details about the biochemical activities of profilins. In addition to these interactions, plant profilins are major human allergens. With the interesting exception of vaccinia virus profilin, all well characterized profilins bind actin monomers with micromolar affinity. New spectroscopic assays indicate that Kds for profilins binding Mg-ATP actin (the form in the cytoplasm) are in the range of 0.1 to 0.5 µM. The major contact site in cocrystals of actin and profilin28 is the binding site in solution.
Scryin
Authors: Way Michael 
Published: November 2023

Abstract
Scruin is a 102 kDa actin bundling protein found in the acrosomal process of Limulus sperm, and which is present in a 1:1 molar ratio with actin. The protein consists of two homologous domains, which are predicted to have super-fl-barrel folds, connected by a 200 amino acid residue linker region. Scruin is also complexed with calmodulin, implicating a possible calcium-induced conformational change in scruin during the extension of the acrosomal process.