: Myristoylated alanine‐rich C kinase substrate (MARCKS) is
a widely distributed specific protein kinase C (PKC) substrate and has been
implicated in membrane trafficking, cell motility, secretion, ...cell cycle, and
transformation. We found that amyloid β protein (Aβ) (25‐35) and
Aβ (1‐40) phosphorylate MARCKS in primary cultured rat microglia.
Treatment of microglia with Aβ (25‐35) at 10 nM or
12‐O‐tetradecanoylphorbol 13‐acetate (1.6 nM) led to
phosphorylation of MARCKS, an event inhibited by PKC inhibitors,
staurosporine, calphostin C, and chelerythrine. The Aβ (25‐35)‐induced
phosphorylation of MARCKS was inhibited by pretreatment with the tyrosine
kinase inhibitors genistein and herbimycin A, but not with pertussis toxin.
PKC isoforms α, δ, and £ were identified in microglia by
immunocytochemistry and western blots using isoform‐specific antibodies.
PKC‐δ was tyrosine‐phosphorylated by the treatment of microglia for 10
min with Aβ (25‐35) at 10 nM. Other PKC isoforms α and £ were tyrosine‐phosphorylated by Aβ (25‐35), but only to a small extent. We propose that a tyrosine kinase‐activated PKC pathway is involved in the Aβ (25‐35)‐induced phosphorylation of MARCKS in rat microglia.
Measurements of the superconducting transition temperature, T_c, under hydrostatic pressure via bulk AC susceptibility were carried out on several concentrations of phosphorous substitution in ...BaFe_2(As_{1-x}P_x)_2. The pressure dependence of unsubstituted BaFe_2As_2, phosphorous concentration dependence of BaFe_2(As_{1-x}P_x)_2, as well as the pressure dependence of BaFe_2(As_{1-x}P_x)_2 all point towards an identical maximum T_c of 31 K. This demonstrates that phosphorous substitution and physical pressure result in similar superconducting phase diagrams, and that phosphorous substitution does not induce substantial impurity scattering.
