Elevated dopamine concentration in light-adapted zebrafish retinas is correlated with increased dopamine synthesis and metabolism.

Probing zebrafish (Danio rerio) retinal cryostat sections, collected either 8 h into the light or dark cycle, with an antibody against tyrosine hydroxylase (TH) identified a single population of immunopositive cells in the inner retina. However, the observed labeling patterns were not identical in both sets of tissues - label intensity was brighter in light-adapted tissue. This difference was quantified by probing western blots of retinal homogenates with the same TH antibody, which showed that TH expression increased by 42% in light-adapted tissue.

The relative energetic contributions of dominant P1 pocket versus hydrogen bonding interactions to peptide:class II stability: implications for the mechanism of DM function.

Peptides are bound to MHC class II molecules by an array of hydrogen bonds between conserved MHC class II protein side-chains and the peptide backbone and through interactions between MHC protein pockets and peptide side-chain anchors. The crystal structure of murine I-A(k) protein with peptide shows a network of electrostatic interactions with the P1 aspartic acid anchor and an arginine in the P1 pocket that are thought to constitute the major stabilizing interaction between peptide and MHC. In this paper, have explored the relative energetic contribution of this dominant P1 pocket interaction with that made by a genetically conserved hydrogen bond which is formed by the beta 81 histidine residue and the main chain of the bound peptide.

Conformation of MHC class II I-A(g7) is sensitive to the P9 anchor amino acid in bound peptide.

Type I diabetes is a chronic autoimmune disease resulting in the destruction of insulin-producing beta cells in the pancreas. In humans, disease incidence is linked to expression of specific MHC class II alleles and in mice type I diabetes is associated with the class II allele I-A(g7). I-A(g7) contains a polymorphism that is shared by human class II alleles associated with the disease, at position 57 in the beta chain, in which aspartic acid is changed to a serine.

The chondroitin sulfate form of invariant chain trimerizes with conventional invariant chain and these complexes are rapidly transported from the trans-Golgi network to the cell surface.

Targeting of MHCII-invariant chain complexes from the trans-Golgi network to endosomes is mediated by two di-leucine-based signals present in the cytosolic domain of invariant chain. Generation of this endosomal targeting signal is also dependent on multimerization of the invariant chain cytosolic domain sequences, mediated through assembly of invariant chain into homotrimers. A small subset of invariant chain is modified by the addition of chondroitin sulfate and is expressed on the cell surface in association with MHCII.

Correlation of metabolism with tissue carbon and nitrogen turnover rate in small mammals.

Stable isotopes have proven to be a useful tool for deciphering food webs, examining migration patterns and determining nutrient resource allocation. In order to increase the descriptive power of isotopes, an increasing number of studies are using them to model tissue turnover. However, these studies have, mostly by necessity, been largely limited to laboratory experiments and the demand for an easier method of estimating tissue turnover in the field for a large variety of organisms remains.