The 6-min walk distance: change over time and value as a predictor of survival in severe COPD. V.M. Pinto-Plata, C. Cote, H. Cabral, J. Taylor, B.R. Celli. #ERS Journals Ltd 2004. ABSTRACT: The 6-min walk distance (6MWD) is used to evaluate the functional capacity of patients with chronic obstructive pulmonary disease (COPD). The change in 6MWD over time and its correlation with changes in spirometry and survival are unclear.Patients (n=198) with severe COPD and 41 age-matched controls were followed for 2 yrs, and anthropometrics, spirometry, 6MWD and comorbidities were measured.The 6MWD decreased in the COPD group from 238¡107 m to 218¡112 m (-26¡37 m?yr -1 ), and increased in the control group from 532¡82 m to 549¡86 m (12¡25 m?yr -1 ). In both groups, there was a poor correlation with changes in forced expiratory volume in one second (FEV1). Nonsurvivors in the COPD group (42%) had a more pronounced change in the 6MWD (-40 versus -22 m?yr -1 ) but a similar change in FEV1 (118 versus 102 mL?yr -1 ). The 6MWD independently predicted survival, after accounting for age, body mass index, FEV1 and comorbidities.In severe chronic obstructive pulmonary disease, the 6-min walk distance predicts mortality better than other traditional markers of disease severity. Its measurement is useful in the comprehensive evaluation of patients with severe disease.

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 p2l"GAP; 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 Mrs of 62,000 and 130,000 was inhibited by incubation with a Src S13 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.The Src family of protein tyrosine kinases contains two conserved domains, the Src homology 2 (SH2) and Src homology 3 (SH3) domains. SH2 and SH3 domains mediate intramolecular and intermolecular binding interactions which regulate the functional activity of these proteins in intracellular signal transduction pathways (20,37,38). The intermolecular protein-protein interactions couple Src family kinases with proteins which serve as protein substrates or which determine the subcellular localization of these enzymes (5, 20). The intramolecular binding interactions mediated by SH2 and SH3 domains regulate the catalytic activity of these kinases (20, 50, 56). SH2 and SH3 domains are also found in other protein tyrosine kinases (e.g., Abl, Fps, Syk, and Zap) as well as in cellular proteins otherwise unrelated to Src family kinases (38). These proteins include enzymes (e.g., phospholipase C--y, p21aSGAP [a Ras GTPase-activating protein], and the p85 subunit of phosphatidylinositol 3'-kinase [p85-PI-3K]), transcription factors (e.g., the p113, p91, and p84 subunits of interferon-stimulated gene factor 3), cytoskeletal proteins (e.g., tensin, cortactin, myosin 1B, and a-spectrin), and adaptor proteins that appear to serve exclusively as coupling factors that link proteins involved in signaling pathways (e.g., Grb-2/ Sem5, Nck, and Crk) (6,8,14,20,28,31,37,38 and SH3 domains are commonly found together in intracellular p...

Many proteins involved in intracellular signal transduction contain a small, 50‐60 amino acid domain, termed the Src homology 3 (SH3) domain. This domain appears to mediate critical protein‐protein interactions that are involved in responses to extracellular signals. Previous studies have shown that the SH3 domains from several proteins recognize short, contiguous amino acid sequences that are rich in proline residues. While all SH3 recognition sequences identified to date share a conserved P‐X‐X‐P motif, the sequence recognition specificity of individual SH3 domains is poorly understood. We have employed a novel modification of phage display involving biased libraries to identify peptide ligands of the Src, Fyn, Lyn, PI3K and Abl SH3 domains. With biased libraries, we probed SH3 recognition over a 12 amino acid window. The Src SH3 domain prefers the sequence XXXRPLPPLPXP, Fyn prefers XXXRPLPP(I/L)PXX, Lyn prefers RXXRPLPPLPXP, PI3K prefers RXXRPLPPLPP while the Abl SH3 domain selects phage containing the sequence PPPYPPPP(I/V)PXX. We have also analysed the binding properties of Abl and Src SH3 ligands. We find that although the phage‐displayed Abl and Src SH3 ligands are proline rich, they are distinct. In surface plasmon resonance binding assays, these SH3 domains displayed highly selective binding to their cognate ligands when the sequences were displayed on the surface of the phage or as synthetic peptides. The selection of these high affinity SH3 peptide ligands provides valuable information on the recognition motifs of SH3 domains, serve as new tools to interfere with the cellular functions of SH3 domain‐mediated processes and form the basis for the design of SH3‐specific inhibitors of disease pathways.

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia (MED) are relatively common skeletal dysplasias resulting in short-limbed dwarfism, joint pain, and stiffness. PSACH and the largest proportion of autosomal dominant MED (AD-MED) results from mutations in cartilage oligomeric matrix protein (COMP); however, AD-MED is genetically heterogenous and can also result from mutations in matrilin-3 (MATN3) and type IX collagen (COL9A1, COL9A2, and COL9A3). In contrast, autosomal recessive MED (rMED) appears to result exclusively from mutations in sulphate transporter solute carrier family 26 (SLC26A2). The diagnosis of PSACH and MED can be difficult for the nonexpert due to various complications and similarities with other related diseases and often mutation analysis is requested to either confirm or exclude the diagnosis. Since 2003, the European Skeletal Dysplasia Network (ESDN) has used an on-line review system to efficiently diagnose cases referred to the network prior to mutation analysis. In this study, we present the molecular findings in 130 patients referred to ESDN, which includes the identification of novel and recurrent mutations in over 100 patients. Furthermore, this study provides the first indication of the relative contribution of each gene and confirms that they account for the majority of PSACH and MED. Hum Mutat 33:144–157, 2012. © 2011 Wiley Periodicals, Inc.