scholarly journals Determinants of the Src Homology Domain 3-Like Fold

2003 ◽  
Vol 185 (14) ◽  
pp. 4081-4086 ◽  
Author(s):  
J. Alejandro D'Aquino ◽  
Dagmar Ringe

ABSTRACT In eukaryotes, the Src homology domain 3 (SH3) is a very important motif in signal transduction. SH3 domains recognize poly-proline-rich peptides and are involved in protein-protein interactions. Until now, the existence of SH3 domains has not been demonstrated in prokaryotes. However, the structure of the C-terminal domain of DtxR clearly shows that the fold of this domain is very similar to that of the SH3 domain. In addition, there is evidence that the C-terminal domain of DtxR binds to poly-proline-rich regions. Other bacterial proteins have domains that are structurally similar to the SH3 domain but whose functions are unknown or differ from that of the SH3 domain. The observed similarities between the structures of the C-terminal domain of DtxR and the SH3 domain constitute a perfect system to gain insight into their function and information about their evolution. Our results show that the C-terminal domain of DtxR shares a number of conserved key hydrophobic positions not recognizable from sequence comparison that might be responsible for the integrity of the SH3-like fold. Structural alignment of an ensemble of such domains from unrelated proteins shows a common structural core that seems to be conserved despite the lack of sequence similarity. This core constitutes the minimal requirements of protein architecture for the SH3-like fold.

1993 ◽  
Vol 340 (1293) ◽  
pp. 279-285 ◽  

The targets of receptor protein-tyrosine kinases are characterized by Src homology 2 (SH2) domains, that mediate specific interactions with receptor autophosphorylation sites. SH 2-mediated interactions are important for the activation of biochemical signalling pathways in cells stimulated with growth factors. A distinct protein module, the SH3 domain, is frequently found in polypeptides that contain SH2 domains, and is also implicated in controlling protein-protein interactions in signal transduction. Evidence suggesting that SH2 and SH3 domains act synergistically in stimulation of the Ras pathway is discussed.


2007 ◽  
Vol 35 (5) ◽  
pp. 966-969 ◽  
Author(s):  
S. Rotem ◽  
C. Katz ◽  
A. Friedler

ASPP (apoptosis-stimulating protein of p53) 2 is a pro-apoptotic protein that stimulates the p53-mediated apoptotic response. Here, we provide an overview of the structure and protein–protein interactions of ASPP2. The C-terminus of ASPP2 contains Ank (ankyrin) repeats and an SH3 domain (Src homology 3 domain). The Ank–SH3 domains mediate interactions between ASPP2 and numerous proteins involved in apoptosis such as p53 and Bcl-2. The proline-rich domain of ASPP2 is unfolded in its native state, but was not shown to mediate intermolecular interactions. Instead, it makes an intramolecular domain–domain interaction with the Ank–SH3 C-terminal domains of ASPP2. This intramolecular interaction between the unstructured proline-rich domain and the structured Ank–SH3 domains in ASPP2, which is possible due to the unfolded nature of the proline-rich domain, is proposed to have an important role in regulating the intermolecular interactions of ASPP2 with its partner proteins.


1998 ◽  
Vol 3 (1) ◽  
pp. 37-41 ◽  
Author(s):  
Anne E. Jones ◽  
Kalle Saksela ◽  
Stephen M. Game ◽  
Gerard O'Beirne ◽  
Neil D. Cook

The interaction between the Human Immunodeficiency Virus Nef protein (HIV-1 Nef) and the Src Homology Region 3 (SH3) domain of Hck was studied using scintillation proximity assay (SPA). SPA is a quick and sensitive method that does not require a separation step, thus allowing assays to be performed in a homogeneous environment. In contrast to most conventional techniques, SPA may also be used to detect low affinity protein-protein interactions. In this study, the assay was configured using biotinylated Hck SH3 domain expressed both as a GST fusion protein and synthesized chemically in its' native form. Biotinylated Hck protein was immobilized to streptavidin-coated fluoromicrosphere SPA beads and the binding of [3H]Nef was detected by scintillation counting. Analysis of binding yielded an average equilibrium dissociation constant (KD) of 183 ± 30 nM for the interaction in line with reported values by other methods. The data presented demonstrates that using SPA, protein-protein interactions of relatively low affinity can be detected with a high degree of sensitivity and screening studies of inhibitors of these associations could be facilitated by the high sample throughput achievable with SPA.


Genes ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 286 ◽  
Author(s):  
Eliza C. Martin ◽  
Octavina C. A. Sukarta ◽  
Laurentiu Spiridon ◽  
Laurentiu G. Grigore ◽  
Vlad Constantinescu ◽  
...  

Leucine-rich-repeats (LRRs) belong to an archaic procaryal protein architecture that is widely involved in protein–protein interactions. In eukaryotes, LRR domains developed into key recognition modules in many innate immune receptor classes. Due to the high sequence variability imposed by recognition specificity, precise repeat delineation is often difficult especially in plant NOD-like Receptors (NLRs) notorious for showing far larger irregularities. To address this problem, we introduce here LRRpredictor, a method based on an ensemble of estimators designed to better identify LRR motifs in general but particularly adapted for handling more irregular LRR environments, thus allowing to compensate for the scarcity of structural data on NLR proteins. The extrapolation capacity tested on a set of annotated LRR domains from six immune receptor classes shows the ability of LRRpredictor to recover all previously defined specific motif consensuses and to extend the LRR motif coverage over annotated LRR domains. This analysis confirms the increased variability of LRR motifs in plant and vertebrate NLRs when compared to extracellular receptors, consistent with previous studies. Hence, LRRpredictor is able to provide novel insights into the diversification of LRR domains and a robust support for structure-informed analyses of LRRs in immune receptor functioning.


1994 ◽  
Vol 14 (7) ◽  
pp. 4509-4521 ◽  
Author(s):  
Z Weng ◽  
S M Thomas ◽  
R J Rickles ◽  
J A Taylor ◽  
A W Brauer ◽  
...  

Src homology 3 (SH3) domains mediate protein-protein interactions necessary for the coupling of cellular proteins involved in intracellular signal transduction. We previously established solution-binding conditions that allow affinity isolation of Src SH3-binding proteins from cellular extracts (Z. Weng, J. A. Taylor, C. E. Turner, J. S. Brugge, and C. Seidel-Dugan, J. Biol. Chem. 268:14956-14963, 1993). In this report, we identified three of these proteins: Shc, a signaling protein that couples membrane tyrosine kinases with Ras; p62, a protein which can bind to p21rasGAP; and heterogeneous nuclear ribonucleoprotein K, a pre-mRNA-binding protein. All of these proteins contain proline-rich peptide motifs that could serve as SH3 domain ligands, and the binding of these proteins to the Src SH3 domain was inhibited with a proline-rich Src SH3 peptide ligand. These three proteins, as well as most of the other Src SH3 ligands, also bound to the SH3 domains of the closely related protein tyrosine kinases Fyn and Lyn. However, Src- and Lyn-specific SH3-binding proteins were also detected, suggesting subtle differences in the binding specificity of the SH3 domains from these related proteins. Several Src SH3-binding proteins were phosphorylated in Src-transformed cells. The phosphorylation of these proteins was not detected in cells transformed by a mutant variant of Src lacking the SH3 domain, while there was little change in tyrosine phosphorylation of other Src-induced phosphoproteins. In addition, the coprecipitation of v-Src with two tyrosyl-phosphorylated proteins with M(r)s of 62,000 and 130,000 was inhibited by incubation with a Src SH3 peptide ligand, suggesting that the binding of these substrate proteins is dependent on interactions with the SH3 domain. These results strongly suggest a role for the Src SH3 domain in the recruitment of substrates to this protein tyrosine kinase, either through direct interaction with the SH3 domain or indirectly through interactions with proteins that bind to the SH3 domain.


2009 ◽  
Vol 390 (8) ◽  
Author(s):  
Reinhard Krämer ◽  
Christine Ziegler

Abstract Activation of the osmoregulated trimeric betaine transporter BetP from Corynebacterium glutamicum was shown to depend mainly on the correct folding and integrity of its 55 amino acid long, partly α-helical C-terminal domain. Reorientation of the three C-terminal domains in the BetP trimer indicates different lipid-protein and protein-protein interactions of the C-terminal domain during osmoregulation. A regulation mechanism is suggested where this domain switches the transporter from the inactive to the active state. Interpretation of recently obtained electron and X-ray crystallography data of BetP led to a structure-function based model of C-terminal molecular switching involved in osmoregulation.


2012 ◽  
Vol 5 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Natalya Kurochkina ◽  
Udayan Guha

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1084 ◽  
Author(s):  
Chana G. Sokolik ◽  
Nasrin Qassem ◽  
Jordan H. Chill

WASp-interacting protein (WIP), a regulator of actin cytoskeleton assembly and remodeling, is a cellular multi-tasker and a key member of a network of protein–protein interactions, with significant impact on health and disease. Here, we attempt to complement the well-established understanding of WIP function from cell biology studies, summarized in several reviews, with a structural description of WIP interactions, highlighting works that present a molecular view of WIP’s protein–protein interactions. This provides a deeper understanding of the mechanisms by which WIP mediates its biological functions. The fully disordered WIP also serves as an intriguing example of how intrinsically disordered proteins (IDPs) exert their function. WIP consists of consecutive small functional domains and motifs that interact with a host of cellular partners, with a striking preponderance of proline-rich motif capable of interactions with several well-recognized binding partners; indeed, over 30% of the WIP primary structure are proline residues. We focus on the binding motifs and binding interfaces of three important WIP segments, the actin-binding N-terminal domain, the central domain that binds SH3 domains of various interaction partners, and the WASp-binding C-terminal domain. Beyond the obvious importance of a more fundamental understanding of the biology of this central cellular player, this approach carries an immediate and highly beneficial effect on drug-design efforts targeting WIP and its binding partners. These factors make the value of such structural studies, challenging as they are, readily apparent.


1990 ◽  
Vol 87 (21) ◽  
pp. 8622-8626 ◽  
Author(s):  
M. F. Moran ◽  
C. A. Koch ◽  
D. Anderson ◽  
C. Ellis ◽  
L. England ◽  
...  

2019 ◽  
Author(s):  
Guillaume Marmier ◽  
Martin Weigt ◽  
Anne-Florence Bitbol

AbstractDetermining which proteins interact together is crucial to a systems-level understanding of the cell. Recently, algorithms based on Direct Coupling Analysis (DCA) pairwise maximum-entropy models have allowed to identify interaction partners among the paralogs of ubiquitous prokaryotic proteins families, starting from sequence data alone. Since DCA allows to infer the three-dimensional structure of protein complexes, its success in predicting protein-protein interactions could be mainly based on contacting residues coevolving to remain physicochemically complementary. However, interacting proteins often possess similar evolutionary histories, which also gives rise to correlations among their sequences. What is the role of purely phylogenetic correlations in the performance of DCA-based methods to infer interaction partners? To address this question, we employ controlled synthetic data that only involves phylogeny and no interactions or contacts. We find that DCA accurately identifies the pairs of synthetic sequences that only share evolutionary history. It performs as well as methods explicitly based on sequence similarity, and even slightly better with large and accurate training sets. We further demonstrate the ability of these various methods to correctly predict pairings among actual paralogous proteins with genome proximity but no known direct physical interaction, which illustrates the importance of phylogenetic correlations in real data. However, for actually interacting and strongly coevolving proteins, DCA and mutual information outperform sequence similarity.Author summaryMany biologically important protein-protein interactions are conserved over evolutionary time scales. This leads to two different signals that can be used to computationally predict interactions between protein families and to identify specific interaction partners. First, the shared evolutionary history leads to highly similar phylogenetic relationships between interacting proteins of the two families. Second, the need to keep the interaction surfaces of partner proteins biophysically compatible causes a correlated amino-acid usage of interface residues. Employing simulated data, we show that the shared history alone can be used to detect partner proteins. Similar accuracies are achieved by algorithms comparing phylogenetic relationships and by coevolutionary methods based on Direct Coupling Analysis, which are a priori designed to detect the second type of signal. Using real sequence data, we show that in cases with shared evolutionary but without known physical interactions, both methods work with similar accuracy, while for physically interacting systems, methods based on correlated amino-acid usage outperform purely phylogenetic ones.


Sign in / Sign up

Export Citation Format

Share Document