Specific Residues in Plasmatocyte-spreading Peptide Are Required for Receptor Binding and Functional Antagonism of Insect Immune Cells

Plasmatocyte-spreading peptide (PSP) plays a central role in insect cellular immune defenses against bacterial infection.

Insect hemocytes (blood cells) are a central part of the insect's cellular response to bacterial pathogens, and these specialist cells can both recognize and engulf bacteria. During this process, hemocytes undergo poorly characterized changes in adhesiveness. Previously, a peptide termed plasmatocyte-spreading peptide (PSP), which induces the adhesion and spreading of plasmatocytes on foreign s...

Identification of specific calcitonin-like receptor residues important for calcitonin gene-related peptide high affinity binding

BACKGROUND Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide whose biological activity has potential therapeutic value for many vascular related diseases. CGRP is a 37 amino acid neuropeptide that signals through a G protein-coupled receptor belonging to the secretin receptor family. Previous studies on the calcitonin-like receptor (CLR), which requires co-expression of the re...

Bacterial challenge and eicosanoids act in plasmatocyte spreading

We report on experiments designed to more thoroughly document the roles of eicosanoids as crucial elements in cell spreading and on experiments designed to test the hypothesis that in vivo bacterial infections influence cell spreading on glass surfaces. We used hemocytes prepared from tobacco hornworms, Manduca sexta (L.) (Lepidoptera: Sphingidae) and four species of bacteria ( Serratia marcesc...

Required for Recognition by CD94/NKG2 and Contact Residues in Bound Peptide Analysis of HLA-E Peptide-Binding Specificity

Are binding residues conserved?

We present our attempt to quantify the evolutionary dynamics of functional residues in a representative set of protein structures and their homologous sequences. Using the log-odds formalism, the preference for all twenty amino acids to be conserved or participate in binding (or active) sites is examined. It appears that while there is a tendency for functional residues to be conserved, the two...