Communication between the ERRalpha homodimer interface and the PGC-1alpha binding surface via the helix 8-9 loop.

Although structural studies on the ligand-binding domain (LBD) have established the general mode of nuclear receptor (NR)/coactivator interaction, determinants of binding specificity are only partially understood. The LBD of estrogen receptor-alpha (ERalpha), for example, interacts only with a region of peroxisome proliferator-activated receptor coactivator (PGC)-1alpha, which contains the canonical LXXLL motif (NR box2), whereas the LBD of estrogen-related receptor-alpha (ERRalpha) also binds efficiently an untypical, LXXYL-containing region (NR box3) of PGC-1alpha. Surprisingly, in a previous structural study, the ERalpha LBD has been observed to bind NR box3 of transcriptional intermediary factor (TIF)-2 untypically via LXXYL, whereas the ERRalpha LBD binds this region of TIF-2 only poorly.

Secretory phospholipase A2 group V: lesion distribution, activation by arterial proteoglycans, and induction in aorta by a Western diet.

Objective: To study the distribution of group V secretory phospholipase A2 (sPLA2) in human and mouse lesions and compare its expression by human vascular cells, its activity toward lipoproteins, and the interaction with arterial proteoglycans (proteoglycans) with those of sPLA2-IIA. In addition, we also investigated the effect of a Western diet and lipopolysaccharide challenge on the aortic expression of these enzymes in mouse models.

Methods And Results: Immunohistochemistry showed sPLA2-V in human and mouse lesions to be associated with smooth muscle cells and also surrounding foam cells in lipid core areas.

Limited mutagenesis increases the stability of human carboxypeptidase U (TAFIa) and demonstrates the importance of CPU stability over proCPU concentration in down-regulating fibrinolysis.

Procarboxypeptidase U [proCPU, thrombin-activatable fibrinolysis inhibitor (TAFI), EC 3.4.17.

Overexpression and functional characterisation of the human melanocortin 4 receptor in Sf9 cells.

The human melanocortin 4 receptor (MC4r) was successfully expressed in Sf9 cells using the baculovirus infection system. N- and C-terminally His-tagged receptors generated B(max) values of 14 and 23 pmol receptor/mg membrane protein, respectively. The highest expression level obtained with the C-terminally His-tagged MC4r corresponded to 0.

Effects of pH, salt and time on ligand binding properties of overexpressed melanocortin 4 receptor.

The G-protein coupled melanocortin 4 receptor (MC4r) plays an important role in the energy metabolism. We overexpressed the MC4r in CHO cells and performed characterisation studies on the cell membranes to determine functional stability and ligand binding properties of the receptor. The affinity for the ligands [Nle4, d-Phe7]-alphaMSH and MTII was lost below pH 6 but could be restored by returning to physiological pH.