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PubMed1998

Molecular cloning and heterologous expression of a glutathione S-transferase involved in insecticide resistance from the diamondback moth, Plutella xylostella.

Four glutathione S-transferase (GST, EC 2.5.1.18) isozymes have been characterized in the larvae of the diamondback moth (DBM), Plutella xylostella L., a cosmopolitan insect pest of crucifiers. This work aimed at cloning and heterologously expressing the cDNA of DBM GST-3, an isozyme involved in this insect resistance to some organophosphorus insecticides, and studying the molecular basis for its increased expression in the resistant strains. Reverse-transcription polymerase chain reaction (RT-PCR) using midgut mRNA from a methyl parathion resistant MPA strain and degenerate primers complimentary to the N-terminal and internal amino acid sequences of GST-3 generated a 128 bp DNA product. A clone of 809 bp, obtained by screening a midgut cDNA library of MPA strain using this PCR product as probe, encoded a protein of 216 amino acids (calculated Mr 24,083 and pI 8.50). This GST of DBM, PxGST3, shared the highest (46.3%) amino acid sequence identity, among insects, to MsGST1 of Manduca sexta. PxGST3 mRNA level was considerably higher in MPA than in susceptible strains, and Southern blots suggested that gene amplification was probably not involved in the increased expression of this GST isozyme. Enzymatically active PxGST3 expressed heterologously in E. coli exhibited similar biochemical and toxicological properties as GST-3 purified from DBM larvae. It is the first cloned GST with a well-defined role in insecticide resistance.

Amino Acid Sequence↗
PubMed2000

Heterologous expression of xenobiotic mammalian-metabolizing enzymes in mutagenicity tester bacteria: an update and practical considerations.

There is an increasing need for metabolic competent cell systems for the mechanistic studies of biotransformation of xenobiotics in toxicology in general and in genotoxicology in particular. These cell systems combine the heterologous expression of a particular mammalian biotransformation enzyme with a specific target/ end point by which a functional analysis of the expressed gene product in the (geno)toxicity of chemicals can be performed. cDNAs of an increasing number of mammalian biotransformation enzymes is being cloned. The construction of specific expression vectors permits their heterologous expression in laboratory bacteria, such as Escherichia coli strains. This development does not only allow biochemical and enzymatic studies of (pure) enzyme preparations but also facilitates the engineering of metabolically competent mutagenicity tester bacteria, thereby providing new tools for genotoxicity testing and for studying of the roles of biotransformation in chemical carcinogenesis. In this review, we describe an update as well as an evaluation of enzymes expressed in mutagenicity tester bacteria. Four types of biotransformation enzymes are now expressed in these bacteria, namely, GSTs, CYPs, NATs, and STs. The expression of these enzymes in the tester bacteria and their subsequent application in mutagenicity assays demonstrates that heterologous expression in this type of bacteria has a number implications for the functionality of the biotransformation enzymes as well as for the functioning of the tester bacteria in mutagenicity detection. We also describe here a number of practical considerations in this regard.

Animals↗
PubMed2004

Heterologous expression of human {alpha}6{beta}4{beta}3{alpha}5 nicotinic acetylcholine receptors: binding properties consistent with their natural expression require quaternary subunit assembly including the {alpha}5 subunit.

Heterologous expression and lesioning studies were conducted to identify possible subunit assembly partners in nicotinic acetylcholine receptors (nAChR) containing alpha6 subunits (alpha6(*) nAChR). SH-EP1 human epithelial cells were transfected with the requisite subunits to achieve stable expression of human alpha6beta2, alpha6beta4, alpha6beta2beta3, alpha6beta4beta3, or alpha6beta4beta3alpha5 nAChR. Cells expressing subunits needed to form alpha6beta4beta3alpha5 nAChR exhibited saturable [(3)H]epibatidine binding (K(d) = 95.9 +/- 8.3 pM and B(max) = 84.5 +/- 1.6 fmol/mg of protein). The rank order of binding competition potency (K(i)) for prototypical nicotinic compounds was alpha-conotoxin MII (6 nM) > nicotine (156 nM) approximately methyllycaconitine (200 nM) > alpha-bungarotoxin (>10 microM), similar to that for nAChR in dopamine neurons displaying a distinctive pharmacology. 6-Hydroxydopamine lesioning studies indicated that beta3 and alpha5 subunits are likely partners of the alpha6 subunits in nAChR expressed in dopaminergic cell bodies. Similar to findings in rodents, quantitative real-time reverse transcription-polymerase chain reactions of human brain indicated that alpha6 subunit mRNA expression was 13-fold higher in the substantia nigra than in the cortex or the rest of the brain. Thus, heterologous expression studies suggest that the human alpha5 subunit makes a critical contribution to alpha6beta4beta3alpha5 nAChR assembly into a ligand-binding form with native alpha6(*)-nAChR-like pharmacology and of potential physiological and pathophysiological relevance.

Animals↗
PubMed1996

Interactions between microsomal triglyceride transfer protein and apolipoprotein B within the endoplasmic reticulum in a heterologous expression system.

When apolipoprotein B (apoB) is expressed in heterologous cells, it is not secreted but retained and degraded within the endoplasmic reticulum (ER). We have previously characterized carboxyl-terminal truncated forms of apoB expressed in COS cells and have shown that these proteins were readily synthesized but retained within the ER and degraded, if the size of the truncated protein was larger than apoB 29. Below this size, the smaller the size of the apoB truncates, the greater the extent of secretion, although >50% of these smaller proteins were also degraded within the ER. In the present study, we demonstrate that this secretory defect can be overcome by coexpression with microsomal triglyceride transfer protein (MTP); moreover, this complementation is inversely related to the size of apoB. Secretion of apoBs larger than B29 required the coexpression of MTP and, in the presence of MTP, was oleate-responsive. MTP, in the presence or absence of oleate supplementation, had little or no effect on the secretion of the shorter truncates. We discovered, however, that MTP was physically associated with all forms of apoB intracellularly (B13-B41). The association of MTP with apoB 41 was stable to high salt washing, as well as to low pH, suggesting that these interactions may be hydrophobic in nature. In addition to the interaction with MTP, apoB was also found to be associated with calnexin, confirming previous studies, and with proteins bearing the KDEL retention signal. However, studies on overexpression of human calnexin and tunicamycin inhibition of glycosylation showed that interaction with calnexin was not necessary for the formation or secretion of apoB 41-containing lipoproteins; moreover, in the presence of MTP, the association of calnexin with apoB 41 was transient or absent. These data suggest that for apoB to attain a folded state sufficient to escape the quality control of the ER, it needs to obtain neutral lipid (supplied by MTP), as well as its ability to keep it packaged as a rudimentary lipoprotein, dependent on its size being larger than B29.

Amino Acid Sequence↗
PubMed2004

Heterologous expression of the modified coat protein of Cowpea chlorotic mottle bromovirus results in the assembly of protein cages with altered architectures and function.

We have developed methods for producing viral-based protein cages in high yield that are amenable to genetic modification. Expression of the structural protein of Cowpea chlorotic mottle bromovirus (CCMV) using the yeast-based Pichia pastoris heterologous expression system resulted in the assembly of particles that were visibly indistinguishable from virus particles produced in the natural host. We have shown that a collection of non-infectious CCMV coat protein mutants expressed in the P. pastoris system assemble into viral protein cages with altered architectures and function. This provides an alternative to other heterologous expression systems for production of viral structural proteins in which expression has resulted in unassembled cages. Heterologous expression in P. pastoris further enhances the development of viral-based protein cages as biotemplates for nanotechnology and for future studies examining details of icosahedral virus assembly.

Bromovirus↗
PubMed2000

Optimizing heterologous expression in dictyostelium: importance of 5' codon adaptation.

Expression of heterologous proteins in Dictyostelium discoideum presents unique research opportunities, such as the functional analysis of complex human glycoproteins after random mutagenesis. In one study, human chorionic gonadotropin (hCG) and human follicle stimulating hormone were expressed in Dictyostelium. During the course of these experiments, we also investigated the role of codon usage and of the DNA sequence upstream of the ATG start codon. The Dictyostelium genome has a higher AT content than the human, resulting in a different codon preference. The hCG-beta gene contains three clusters with infrequently used codons that were changed to codons that are preferred by Dictyostelium. The results reported here show that optimizing the first 5-17 codons of the hCG gene contributes to 4- to 5-fold increased expression levels, but that further optimization has no significant effect. These observations suggest that optimal codon usage contributes to ribosome stabilization, but does not play an important role during the elongation phase of translation. Furthermore, adapting the 5'-sequence of the hCG gene to the Dictyostelium 'Kozak'-like sequence increased expression levels approximately 1.5-fold. Thus, using both codon optimization and 'Kozak' adaptation, a 6- to 8-fold increase in expression levels could be obtained for hCG.

Amino Acid Sequence↗
PubMed1998

Heterologous expression of the Desulfovibrio gigas [NiFe] hydrogenase in Desulfovibrio fructosovorans MR400.

The ability of Desulfovibrio fructosovorans MR400 DeltahynABC to express the heterologous cloned [NiFe] hydrogenase of Desulfovibrio gigas was investigated. The [NiFe] hydrogenase operon from D. gigas, hynABCD, was cloned, sequenced, and introduced into D. fructosovorans MR400. A portion of the recombinant heterologous [NiFe] hydrogenase was totally matured, exhibiting catalytic and spectroscopic properties identical to those of the native D. gigas protein. A chimeric operon containing hynAB from D. gigas and hynC from D. fructosovorans placed under the control of the D. fructosovorans hynAp promoter was constructed and expressed in D. fructosovorans MR400. Under these conditions, the same level of activity was obtained as with the D. gigas hydrogenase operon.

Amino Acid Sequence↗
PubMed1999

Modulation of invasive properties of murine squamous carcinoma cells by heterologous expression of cathepsin B and cystatin C.

Murine SCC-VII squamous carcinoma cells have the capacity to penetrate reconstituted basement membranes (Matrigel) in vitro. The invasion of Matrigel layers by SCC-VII cells was significantly reduced by E-64, a specific inhibitor of lysosomal cysteine proteinases. The cathepsin-B-selective E-64 derivative, CA-074, inhibited penetration of Matrigel by SCC-VII cells to the same extent, indicating a major role for this particular lysosomal enzyme in extracellular-matrix degradation during squamous-carcinoma-cell invasion. SCC-VII cells were stably transfected with a cDNA encoding human procathepsin B, in an attempt to modulate the invasive properties of the cell line. The transfected cells expressed the heterologous gene, secreted increased amounts of procathepsin B and displayed enhanced invasive potential. In vivo, the activity of cathepsin B is strictly regulated by endogenous inhibitors. SCC-VII cells were therefore also stably transfected with a cDNA encoding human cystatin C, the most potent cysteine-proteinase inhibitor in mammalian tissues. The expression of this transgene resulted in the production of active recombinant cystatin C and a pronounced reduction in Matrigel invasion. These studies demonstrate that the invasive properties of squamous-cell carcinomas can be changed by modulation of the balance between cathepsin B and its endogenous inhibitors, and provide further evidence for the involvement of this lysosomal cysteine proteinase in tumour invasion and metastasis.

Animals↗
PubMed2006

Heterologous expression of tylosin polyketide synthase and production of a hybrid bioactive macrolide in Streptomyces venezuelae.

Tylosin polyketide synthase (Tyl PKS) was heterologously expressed in an engineered strain of Streptomyces venezuelae bearing a deletion of pikromycin PKS gene cluster using two compatible low-copy plasmids, each under the control of a pikAI promoter. The mutant strain produced 0.5 mg/l of the 16-membered ring macrolactone, tylactone, after a 4-day culture, which is a considerably reduced culture period to reach the maximum production level compared to other Streptomyces hosts. To improve the production level of tylactone, several precursors for ethylmalonyl-CoA were fed to the growing medium, leading to a 2.8-fold improvement (1.4 mg/ml); however, switching the pikAI promoter to an actI promoter had no observable effect. In addition, a small amount of desosamine-glycosylated tylactone was detected from the extract of the mutant strain, revealing that the native glycosyltransferase DesVII displayed relaxed substrate specificity in accepting the 16-membered ring macrolactone to produce the glycosylated tylactone. These results demonstrate a successful attempt for a heterologous expression of Tyl PKS in S. venezuelae and introduce S. venezuelae as a rapid heterologous expression system for the production of secondary metabolites.

Anti-Bacterial Agents↗
PubMed2001

Molecular characterization and heterologous expression of hypCD, the first two [NiFe] hydrogenase accessory genes of Thermococcus litoralis.

The hypCD genes, encoding the counterparts of mesophilic proteins involved in the maturation of [NiFe] hydrogenases, were isolated from the hyperthermophilic archaeon Thermococcus litoralis. The deduced gene products showed 30-40% identity to the corresponding mesophilic proteins. HypC and HypD were synthesized by the T7 expression system. Heterologous complementation experiments were done in Escherichia coli and Ralstonia eutropha strains lacking functionally active hypC and hypD genes. Only the cytoplasmic hydrogenase of R. eutropha could be processed by HypD from T. litoralis. This was the first demonstration of mesophilic hydrogenase processing using a hyperthermophilic archaeal accessory protein to produce an active enzyme.

Archaeal Proteins↗
PubMed1987

Cloning and heterologous expression of a gene cluster for the biosynthesis of tetracenomycin C, the anthracycline antitumor antibiotic of Streptomyces glaucescens.

Through complementation of mutations specifically blocking the biosynthesis of tetracenomycin C by Streptomyces glaucescens and selecting for resistance to tetracenomycin C in Streptomyces lividans, all of the genes for the production of tetracenomycin C were inserted in pIJ702, a high copy-number Streptomyces gene cloning vector. The tcm biosynthetic and resistance genes occur as a single cluster in the S. glaucescens genome and are expressed in heterologous streptomycete hosts like S. lividans, resulting in the overproduction of pigmented intermediates of the tetracenomycin C biosynthetic pathway.

Cloning, Molecular↗
PubMed2000

Molecular cloning, heterologous expression, and functional characterisation of a malate synthase gene from Streptomyces coelicolor A3(2).

With the rapid generation of genetic information from the Streptomyces coelicolor genome project, deciphering the relevant gene products is critical for understanding the genetics of this model streptomycete. A putative malate synthase gene (aceB) from S. coelicolor A3(2) was identified by homology-based analysis, cloned by polymerase chain reaction, and fully sequenced on both strands. The putative malate synthase from S. coelicolor has an amino acid identity of 77% with the malate synthase of S. clavuligerus, and possesses an open reading frame which codes for a protein of 540 amino acids. In order to establish the identity of this gene, the putative aceB clones were subcloned into the expression vector pET24a, and heterologously expressed in Escherichia coli BL21(DE3). Soluble cell-free extracts containing the recombinant putative malate synthase exhibited a specific activity of 1623 (nmol.mg-1.min-1), which is an increment of 92-fold compared to the non-recombinant control. Thus, the gene product was confirmed to be a malate synthase. Interestingly, the specific activity of S. coelicolor malate synthase was found to be almost 8-fold higher than the specific activity of S. clavuligerus malate synthase under similar expression conditions. Furthermore, the genomic organisation of the three Streptomyces aceB genes cloned thus far is different from that of other bacterial malate synthases, and warrants further investigation.

Amino Acid Motifs↗
PubMed1992

Heterologous expression, purification, and biochemistry of the oligomycin sensitivity conferring protein (OSCP) from yeast.

Yeast Saccharomyces cerevisiae oligomycin sensitivity conferring proteins (OSCP) have been expressed in Escherichia coli. Heterologous expression results in production of a protein that is identical to yeast mature OSCP, including the absence of the initiating methionine residue. Yeast OSCP expressed in E. coli has been purified to homogeneity and it is able to reconstitute oligomycin-sensitive ATPase using purified F1- and F1/OSCP-depleted membranes (electron transport particles (ETP). Binding of F1 to ETP is dependent on the addition of OSCP. Binding studies using 35S-OSCP indicated that OSCP binds to ETP with a Kd of 200 nM and a capacity of 420 pmol/mg particle protein, whereas OSCP does not interact with F1 in the absence of ETP. These data indicate that yeast OSCP must first form a specific complex with F0, which then binds F1 forming the functional complex. To identify functional domains in yeast OSCP, two deletion mutants have been made. Antibodies directed to these deletion products do not inhibit OSCP-dependent binding of F1 to ETP. However, antibodies directed against the last one-third of OSCP greatly reduce the oligomycin sensitivity of the reconstituted ATPase. These data suggest that OSCP is involved in a functional role in energy transduction or proton translocation and serves a structural role in the yeast mitochondrial ATP synthase.

Adenosine Triphosphatases↗
PubMed1995

Heterologous expression, purification, activity and conformational studies of different forms of dianthin 30.

Dianthin 30, a ribosome inactivating protein (RIP) from Dianthus caryophyllus, has been expressed in Escherichia coli. Heterologous expression of a deletion mutant dianthin 30 delta 255-270 resulted in the production of a protein identical to carnation mature dianthin 30, including the absence at the carboxy-terminal of a putative 16 amino acid long pro-signal peptide. The production of a form of dianthin 30, which includes the pro-signal, is described as well. Both dianthin 30 delta 255-270 and dianthin 30 expressed in E. coli are mainly localized (90%) in the soluble fraction. Dianthin 30 delta 255-270 and dianthin 30 have been purified to homogeneity and were shown to inhibit protein synthesis in vitro with an IC50 of 8 and of 11 ng/ml, respectively. Secondary structure analysis, carried out by circular dichroism spectroscopy, indicated that the naturally occurring and the recombinant forms of dianthin 30 and dianthin 30 delta 255-270 possess the same secondary structure composition, accounting for an alpha + beta type architecture. RIPs as immunotoxins in clinical trial and as mitotoxins in experimental models have been extremely efficacious. In addition, growing evidence indicates their effective use as antiviral agents, including in HIV-1 infection. These data indicate the ability to produce either chemically linked or recombinant fusion proteins with dianthin 30 and cell-binding ligands for production of new reagents for clinical and experimental use.

Antiviral Agents↗
PubMed2001

Reduction of wobble-position GC bases in Corynebacteria genes and enhancement of PCR and heterologous expression.

Corynebacteria codon usage exhibits an overall GC content of 67%, and a wobble-position GC content of 88%. Escherichia coli, on the other hand has an overall GC content of 51%, and a wobble-position GC content of 55%. The high GC content of Corynebacteria genes results in an unfavorable codon preference for heterologous expression, and can present difficulties for polymerase-based manipulations due to secondary-structure effects. Since these characteristics are due primarily to base composition at the wobble-position, synthetic genes can, in principle, be designed to eliminate these problems and retain the wild-type amino acid sequence. Such genes would obviate the need for special additives or bases during in vitro polymerase-based manipulation and mutant host strains containing uncommon tRNA's for heterologous expression. We have evaluated synthetic genes with reduced wobble-position G/C content using two variants of the enzyme 2,5-diketo-D-gluconic acid reductase (2,5-DKGR A and B) from Corynebacterium. The wild-type genes are refractory to polymerase-based manipulations and exhibit poor heterologous expression in enteric bacteria. The results indicate that a subset of codons for five amino acids (alanine, arginine, glutamate, glycine and valine) contribute the greatest contribution to reduction in G/C content at the wobble-position. Furthermore, changes in codons for two amino acids (leucine and proline) enhance bias for expression in enteric bacteria without affecting the overall G/C content. The synthetic genes are readily amplified using polymerase-based methodologies, and exhibit high levels of heterologous expression in E. coli.

Base Composition↗
PubMed1998

Single-channel properties of inositol (1,4,5)-trisphosphate receptor heterologously expressed in HEK-293 cells.

The inositol (1,4,5)-trisphosphate receptor (InsP3R) mediates Ca2+ release from intracellular stores in response to generation of second messenger InsP3. InsP3R was biochemically purified and cloned, and functional properties of native InsP3-gated Ca2+ channels were extensively studied. However, further studies of InsP3R are obstructed by the lack of a convenient functional assay of expressed InsP3R activity. To establish a functional assay of recombinant InsP3R activity, transient heterologous expression of neuronal rat InsP3R cDNA (InsP3R-I, SI- SII+ splice variant) in HEK-293 cells was combined with the planar lipid bilayer reconstitution experiments. Recombinant InsP3R retained specific InsP3 binding properties (Kd = 60 nM InsP3) and were specifically recognized by anti-InsP3R-I rabbit polyclonal antibody. Density of expressed InsP3R-I was at least 20-fold above endogenous InsP3R background and only 2-3-fold lower than InsP3R density in rat cerebellar microsomes. When incorporated into planar lipid bilayers, the recombinant InsP3R formed a functional InsP3-gated Ca2+ channel with 80 pS conductance using 50 mM Ba2+ as a current carrier. Mean open time of recombinant InsP3-gated channels was 3.0 ms; closed dwell time distribution was double exponential and characterized by short (18 ms) and long (130 ms) time constants. Overall, gating and conductance properties of recombinant neuronal rat InsP3R-I were very similar to properties of native rat cerebellar InsP3R recorded in identical experimental conditions. Recombinant InsP3R also retained bell-shaped dependence on cytosolic Ca2+ concentration and allosteric modulation by ATP, similar to native cerebellar InsP3R. The following conclusions are drawn from these results. (a) Rat neuronal InsP3R-I cDNA encodes a protein that is either sufficient to produce InsP3-gated channel with functional properties identical to the properties of native rat cerebellar InsP3R, or it is able to form a functional InsP3-gated channel by forming a complex with proteins endogenously expressed in HEK-293 cells. (b) Successful functional expression of InsP3R in a heterologous expression system provides an opportunity for future detailed structure-function characterization of this vital protein.

Amino Acid Sequence↗
PubMed2026

Heterologous expression of DobHLH25 from Dendrobium officinale enhances drought tolerance in Arabidopsis.

Drought stress severely constrains the growth, yield, and accumulation of bioactive compounds in Dendrobium officinale (D. officinale), a valuable medicinal orchid, and this challenge is exacerbated under simulated wild cultivation where plants are inevitably exposed to recurring water deficits. Basic helix-loop-helix (bHLH) transcription factors are well-established regulators of plant abiotic stress responses. However, the molecular mechanisms by which bHLH transcription factors respond to drought stress in this species remain largely unknown. In this study, a bHLH transcription factor gene, DobHLH25, was cloned from D. officinale. Phylogenetic analysis revealed that DobHLH25 shares the highest sequence identity with its ortholog in Dendrobium nobile. Additionally, subcellular localization analysis indicated that DobHLH25 is targeted to the nucleus and possesses a functional transcriptional activation domain. Expression pattern analysis showed that DobHLH25 is most abundantly expressed in old leaves, and its expression in roots, stems, and leaves is induced by polyethylene glycol treatments. Heterologous expression of DobHLH25 in Arabidopsis thaliana resulted in higher seed germination rates and longer root lengths under mannitol-induced osmotic stress compared to wild-type plants. Under drought stress, DobHLH25 heterologous expression lines exhibited higher survival rates, reduced leaf water loss, lower malondialdehyde accumulation, and increased proline content. Moreover, the activities of antioxidant enzymes such as superoxide dismutase and peroxidase were significantly enhanced, and the expression levels of multiple drought-responsive genes were markedly upregulated. Collectively, these findings suggest a correlation between DobHLH25 expression and plant drought tolerance, as evidenced by reduced oxidative damage, increased osmolyte accumulation, enhanced antioxidant enzyme activities, and upregulation of drought-responsive genes. Together, these results suggest that DobHLH25 plays a positive role in drought tolerance, and provides a basis for future dissection of its regulatory network in D. officinale.

Drought Resistance↗
PubMed2002

Cell surface targeting and clustering interactions between heterologously expressed PSD-95 and the Shal voltage-gated potassium channel, Kv4.2.

Kv4.2 is a voltage-gated potassium channel that is critical in controlling the excitability of myocytes and neurons. Processes that influence trafficking and surface distribution patterns of Kv4.2 will affect its ability to contribute to cellular functions. The scaffolding/clustering protein PSD-95 regulates trafficking and distribution of several receptors and Shaker family Kv channels. We therefore investigated whether the C-terminal valine-serine-alanine-leucine (VSAL) of Kv4.2 is a novel binding motif for PSD-95. By using co-immunoprecipitation assays, we determined that full-length Kv4.2 and PSD-95 interact when co-expressed in mammalian cell lines. Mutation analysis in this heterologous expression system showed that the VSAL motif of Kv4.2 is necessary for PSD-95 binding. PSD-95 increased the surface expression of Kv4.2 protein and caused it to cluster, as shown by deconvolution microscopy and biotinylation assays. Deleting the C-terminal VSAL motif of Kv4.2 eliminated these effects, as did substituting a palmitoylation-deficient PSD-95 mutant. In addition to these effects of PSD-95 on Kv4.2 distribution, the channel itself promoted redistribution of PSD-95 to the cell surface in the heterologous expression system. This work represents the first evidence that a member of the Shal subfamily of Kv channels can bind to PSD-95, with functional consequences.

Amino Acid Motifs↗