Intracellular mechanisms that mediate mitogenic effects of gastrin remain largely unknown. The present studies were designed to examine if protein tyrosine kinases (PTKs) mediate growth effects of gastrin on a rat intestinal epithelial cell line (IEC-6 cells). Gastrin (< 10 nM) was mitogenic for IEC-6 cells. PTK activity of cell membranes was stimulated in response to 0.01-10.0 nM and 0.05-10.0 microM gastrin in a double biphasic manner. Cells labeled with H3(32)PO4 were stimulated with gastrin and cellular proteins immunoprecipitated with phosphotyrosine antibodies. Endogenous proteins were phosphorylated in a dose- (100% effective dose = 0.1-1.0 nM) and time-dependent manner; at > 10 nM gastrin, the second peak of response was not measured in intact cells. Thus the growth and phosphorylation response of intact cells to gastrin was similar. Both high [dissociation constant (Kd) = 1 nM]- and low (Kd = approximately 0.1 microM)-affinity gastrin binding sites are present on IEC-6 cells. The results of the present study suggest that occupancy of both high- and low-affinity gastrin-binding sites can potentially activate membrane-associated PTKs. However, in intact cells, occupancy of low-affinity sites apparently attenuates kinase activity resulting in reduced protein phosphorylation. Eight protein bands [with relative molecular weight (M(r)) of 32-145 kDa] were tyrosine phosphorylated in intact cells in response to 0.1-1.0 nM gastrin, including two pp60 src-like proteins (with M(r) of 54 and 62 kDa). Thus the growth response pattern of a target cell to gastrin may depend on the stimulation of kinases and other factors (phosphatases?) that phosphorylate and/or dephosphorylate several proteins including c-src-like proteins in a dose-dependent manner.

ZIKV infection has become a global threat spreading across 31 countries in Central America, South America, and the Caribbean. However, little information is available about the molecular epidemiology of ZIKV. Shared mutation of a threonine residue to alanine at the same position in the C terminal of NS5 sequences was observed in sequences from Colombia, Mexico, Panama, and Martinique. The sequences in the phylogenetic tree fell within the same cluster. Based on shared mutation the presence of a Latin American genotype was proposed. Comparison of African and Asian lineages yielded R29N, N273S, H383Q, and P391S mutation. The study highlights that mutation of amino acids at NS5 may contribute to neutropism of ZIKV. J. Med. Virol. 88:1821-1826, 2016. © 2016 Wiley Periodicals, Inc.

Introduction: Globally South-East Asia reported 40% of SARS-CoV-2 infected cases in the fourth week of April 2021. It continued to show an increase with India accounting for 50% of cases worldwide and 30% of global deaths. Genomic surveillance should continue at a rapid pace because of the continuously evolving nature of the virus. The time period of sample collection from the Global Initiative on Sharing All Influenza Data database was concurrent with the surge in new cases seen in the Indian subcontinent. Methodology: 7,415 sequences were downloaded from Global Initiative on Sharing All Influenza Data between January and April 2021; out of which 4,411 were high coverage genome sequences and were considered for analysis. Phylogenetic analysis were carried out using Nextstrain. Results: 21A or B.1.617 or delta was the most prevalent lineage in India accounting for 67.7% of the genomes. Next important clades were 20A, 20B and 20I accounting for 23.6%, 11.8% and 12.1% respectively collected between January 2021 and April 2021. The remaining sequences were assigned to clade 20H, 20J, 20D, 20C, 20G,20E,19A and 19B.The spike mutation frequencies of L452R, E484Q and P681R in Indian state of Maharashtra were 62.4%, 66.5% and 61.5% respectively. Two unique N-terminal domain deletion of spike protein were found at position 67 and 68. Conclusions: The phylogenomics of the delta variant or 21A emerged in neighboring Asian countries of Thailand, Bangladesh, Indonesia and Japan. We analyzed the SARS-CoV-2 genomes from India for mutation characterization of the spike glycoprotein and the nucleocapsid protein.

The serological responses to 2 Mycobacterium leprae specific epitopes and one common mycobacterial antigen were examined in 46 untreated patients with primary neuritic (PN) leprosy. M. leprae specific antibodies to the terminal disaccharide of phenolic glycolipid and/or the ML-04 defined epitope on the 35 kDa protein were detected in 41% of PN patients and 47% responded to one of the 3 antigens. This serological response mirrored that observed in paucibacillary leprosy patients. There was a significant increase in the level of antibody response when more nerve trunks were involved. Changes in antibody levels in seropositive PN patients may prove useful in monitoring the response to chemotherapy.

Pathogenic bacteria use the needle shaped Type III secretion system to inject effector proteins into the host cell. The SopB effector protein of Salmonella mediates invasion by evading the host immune response. Being a phosphoinositide phosphatase, it synthesizes phospholipids at the host cell membrane, after targeting host cell ubiquitin. Ubiquitination of SopB are known to control the biological activity of SopB at the plasma membrane. The identified SopB effector protein of Vibrio vulnificus which is a human pathogen found in the marine environment was homologous to SopB of Salmonella and E.coli. Structural superposition with available structure of SopB of Salmonella yielded a DNA linking domain similar to Salmonella SopB. Ubiquitination sites for SopB homolog in V.vulnificus was predicted by bioinformatics tools which was further supported by molecular docking studies. The ubiquitin binding sites were proposed to be structurally similar to the conserved ubiquitin binding motif of human polymerase complexed with ubiquitin (2KTF). The ubiquitin binding sites having Leu residue at 226, Leu 235 and Leu 234 were conserved whereas the hydrophobic Phe was replaced by Tyr at 223 in the sopB homolog of V.vulnificus. The conserved Glu 228 of SopB protein was predicted to be involved in imparting a electronegative potential in the ligand binding site. The ubiquitin molecule docked with SopB of V.vulnificus had Leu8 for binding interaction and recognition which was found to be similar to the ubiquitin-human polymerase complex. Thus the host immune response was predicted to be targeted by SopB effector in V.vulnificus by altering the ubiquitin pathway. Citation: Adiga R, Karunasagar I, Karunasagar I (2011) Molecular Docking Studies of Type III Secretion System Effector SopB Homolog in Vibrio vulnificus. J Comput Sci Syst Biol 4: 016-020.