We report NMR shift AK and T\ data of 89 Y taken from 77 to 300 K in YBa 2 Cu 3 0 6 +x for 0.35 < x < 1, from the insulating to the metallic state. A Korringa law and therefore a Fermi-liquid picture is found to apply for the spin part K 5 of AK. The spin contribution x*ix 9 T) to Xm is singled out, as the T variation of AK scales linearly with the macroscopic susceptibility # m . This implies that Cu(3

We have developed a system to analyze the specific protein kinase activity of herpes simplex virus 1 Us3 in vitro and shown that Us3 directly phosphorylates viral proteins UL34, ICP22, and Us9 and the cellular protein Bad, previously reported to be putative substrates. Using this system, we determined the phosphorylation sites of UL34 and identified UL31 as a previously unreported, novel substrate of Us3. This system will be useful for further identification of Us3 substrates and their phosphorylation sites, clarification of the role of Us3 in viral replication, and identification of additional Us3 function(s).

UL13 and Us3 are protein kinases encoded by herpes simplex virus 1. We report here that Us3 is a physiological substrate for UL13 in infected cells, based on the following observations. (i) The electrophoretic mobility, in denaturing gels, of Us3 isoforms from Vero cells infected with wild-type virus was slower than that of isoforms from cells infected with a UL13 deletion mutant virus (⌬UL13). After treatment with phosphatase, the electrophoretic mobility of the Us3 isoforms from cells infected with wild-type virus changed, with one isoform migrating as fast as one of the Us3 isoforms from ⌬UL13-infected cells. (ii) A recombinant protein containing a domain of Us3 was phosphorylated by UL13 in vitro. (iii) The phenotype of ⌬UL13 resembles that of a recombinant virus lacking the Us3 gene (⌬Us3) with respect to localization of the viral envelopment factors UL34 and UL31, whose localization has been shown to be regulated by Us3. UL34 and UL31 are localized in a smooth pattern throughout the nuclei of cells infected with wild-type virus, whereas their localization in ⌬UL13-and ⌬Us3-infected cells appeared as nuclear punctate patterns. These results indicate that UL13 phosphorylates Us3 in infected cells and regulates UL34 and UL31 localization, either by phosphorylating Us3 or by a Us3-independent mechanism.Herpes simplex virus 1 (HSV-1) encodes at least three protein kinases, UL13, Us3, and UL39 (63). This report presents studies of the interaction between UL13 and Us3. The background for these studies is as follows.First, UL13 is a serine/threonine protein kinase that is packaged in the tegument, a virion structural component located between the nucleocapsid and the envelope (9,12,13,29,52,68). UL13 plays a role in viral replication in cell cultures, since UL13 deletion mutants exhibit impaired replication in some cell lines, including rabbit skin cells and baby hamster kidney (BHK) cells (10,45,56,57,70). Although the mechanism by which UL13 acts in HSV-1-infected cells remains unclear, infection of rabbit skin cells and BHK cells with UL13 deletion mutants reduces the expression levels of the ␣ protein ICP0 and a subset of ␥ proteins, including UL26, UL26.5, UL38, UL41, and Us11 (56), suggesting that UL13 is involved in viral-gene expression in infected cells. UL13 would also be expected to function in early postinfection events, since tegument proteins are, in general, released into the cytoplasm of newly infected cells. In agreement with this possibility, phosphorylation of a tegument protein by UL13 has been implicated in promoting tegument disassembly in vitro (40).Second, UL13 may function by phosphorylating specific viral and cellular proteins. Thus far, gI/gE, ICP0, ICP22, Us1.5, UL47, UL49, p60, elongation factor 1␦ (EF-1␦), casein kinase II␤ subunit, and RNA polymerase II have been reported to be putative substrates for UL13 (4,10,20,29,32,37,44,51,57,63). However, the biological significance of UL13-mediated phosphorylation in infected cells remains unclear. Since the UL13 amino acid sequence is conse...