No abstract

Brodalumab treatment resulted in significant clinical improvements in patients with moderate-to-severe psoriasis. (Funded by Amgen; AMAGINE-2 and AMAGINE-3 ClinicalTrials.gov numbers, NCT01708603 and NCT01708629.).

Janssen Research & Development.

The distribution of type II Ca2+/calmodulin-dependent protein kinase has been mapped in rat brain by immunochemical and immunohistochemical methods using an antibody against its alpha-subunit. The concentration of the kinase, measured by radioimmunoassay, varies markedly in different brain regions. It is most highly concentrated in the telencephalon where it comprises approximately 2% of the total hippocampal protein, 1.3% of cortical protein, and 0.7% of striatal protein. It is less concentrated in lower brain structures, ranging from about 0.3% of hypothalamic protein to 0.1% of protein in the pons/medulla. The gradient of staining intensity observed in brain sections by immunohistochemistry corroborates this distribution. Neurons and neuropil of the hippocampus are densely stained, whereas little staining is observed in lower brain regions such as the superior colliculus. Within the diencephalon and midbrain, dense staining is observed only in thalamic nuclei and the substantia nigra. The skewed distribution of alpha-subunit appears to be due in part to the occurrence in the cerebellum and pons/medulla of forms of the kinase with a high ratio of beta- to alpha-subunits. However, most of the variation is due to the extremely high concentration of the kinase in particular neurons, especially those of the hippocampus, cortex and striatum. The unusually high expression of the kinase in these neurons is likely to confer upon them specialized responses to calcium ion that are different from those of neurons in lower brain regions.

By three criteria, two biochemical and one immunochemical, the major postsynaptic density protein (mPSDp) is indistinguishable from the 50-kilodalton (kDa) a subunit of a brain calmodulin-dependent protein kinase. First, the two proteins comigrate on NaDodSO4/polyacrylamide gels. Second, iodinated tryptic peptide maps of the two -are identical. Finally, a monoclonal antibody (6G9) that was raised against the protein kinase binds on immunoblots to a single 50 kDa band in crude brain homogenates and to both the a subunit of the purified kinase and the mPSDp from postsynaptic density fractions. The purified kinase holoenzyme also contains a 60-kDa subunit termed 13. A comparison of the peptide map of .8 with the maps of 60-kDa proteins from the postsynaptic density fraction suggests that ,B is present there but is not the only protein present in this molecular weight range. These results indicate that the calmodulin-dependent protein kinase is a major constituent of the postsynaptic density fraction and thus may be a component of type I postsynaptic densities.Many synaptic junctions in the central nervous system contain a prominent specialized structure called the "postsynaptic density" (PSD) (1-5). When viewed by electron microscopy, it is a fibrous, electron-opaque thickening lying opposite the presynaptic terminal, on the cytoplasmic side of the postsynaptic membrane. The morphology of postsynaptic densities is variable. Some are thick [20-60 nm (5)] and appear to cover the entire postsynaptic surface area, whereas others are thin, often discontinuous, patches (1, 6). The former have been termed type I PSDs, while the latter are called-type II (1). Some investigators have suggested that different types of densities are associated with synapses of particular types. For example, type I PSDs most often occur in synapses that are thought to be excitatory (1,7,8), whereas type II PSDs are seen in synapses thought to be inhibitory (9, 10). This hypothesis suggests.that morphologically distinct PSDs may also contain distinct proteins that serve specialized functions associated with their particular transmitter type.In order to understand the structure and function of PSDs, various research groups have developed subcellular fractionation methods to isolate highly enriched preparations of PSDlike material (11-13). These procedures involve osmotic lysis of a subcellular fraction enriched in synaptosomes, followed by purification of junctional membrane complexes and extraction of membrane components by treatment with detergent. The detergent-insoluble residue, purified by density gradient fractionation, consists of electron-opaque, fibrous, disk-shaped structures, 20-60 nm thick and 200-500 nm in diameter (11-15). These structures are -similar in appearance and staining characteristics to type I PSDs in intact fixed tissue, and they are not produced by detergent treatment of other subcellular organelles such as mitochondria or myelin (11). Thus, this subcellular fraction is considered to be highly enriched in type...