Phosphorylation of cytokeratin 17 by herpes simplex virus type 2 US3 protein kinase

We previously reported the establishment of an HEp2 cell line which expresses the US3 protein kinase (PK) of herpes simplex virus type 2 (HSV-2) upon induction with IPTG. Here we report that expression, phosphorylation and ubiquitination of cytokeratin 17 (CK17) are enhanced in US3-expressing HEp2 cells. In vitro kinase and co-immunoprecipitation assays provided evidence that US3 PK directly phosphorylates CK17. Expression of US3 PK caused a significant decrease in filamentous staining of CK17, suggesting that phosphorylation of CK17 by US3 PK causes a disruption of intermediate filaments. Our observations suggest a role for US3 in the regulation of CKs and intermediate filaments in cells. Moreover, we found that infection of a keratinocyte-derived cell line, A431, with a US3-deficient virus, results in cytopathic effects that are morphologically distinct from those induced by wild-type and revertant viruses, suggesting that US3 PK may be important for interaction between HSV-2 and peripheral epithelial cells.     

Detection of herpesvirus DNA in the serum of immunocompetent children

The DNA of herpesviruses such as Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus-6 (HHV6), and human herpesvirus-7 (HHV7) has been detected in the serum of patients with primary infection or with immunosuppression. However, it is unknown how frequently herpesvirus DNA can be detected in the serum of immunocompetent children, or whether the detection of herpesvirus DNA indicates an active infection or virus-related diseases. Using a real-time polymerase chain reaction assay, attempts were made to detect herpesvirus DNA in the serum of 176 ambulatory children who visited a hospital for various reasons. EBV was detected in 4 (2.2%), HHV6 in 4 (2.2%), and HHV7 in 2 (1.1%) of 176 children, but CMV was not detected. Of the 10 positive patients, only 4 were considered, by virtue of clinical and serological characteristics, to have primary infections. The other 4 positive patients had other infections, such as mycoplasma and salmonella. Although herpesvirus DNA could be detected in the serum of immunocompetent children, there was not always a relationship between clinical manifestations and the detection of virus DNA. When herpesvirus DNA is detected in the serum, a careful interpretation is necessary to diagnose a primary infection or a virus-associated disease.     

Molecular phylogeny of symbiotic basidiomycetes of fungus-growing termites in Thailand and their relationship with the host

Termitomyces-related symbiotic basidiomycetes in the nests of fungus-growing termites (Macrotermitinae) of several genera in Thailand were cultivated and analyzed phylogenetically based on the DNA sequence of nuclear ribosomal RNA genes. The relationships of the symbiotic fungi with host termites and their locality were apparently complex, supporting intricate mechanisms for the termites to acquire the symbionts.     

Intercellular trafficking of herpes simplex virus type 2 UL14 deletion mutant proteins

The UL14 gene product of herpes simplex virus is a 32kDa protein expressed late in infection and is a minor component of the virion tegument. We recently showed that the wild-type UL14 protein has heat shock protein (HSP)-like and/or molecular chaperone-like functions. In this study, the intracellular localization of UL14 wild-type and deletion mutant proteins was examined in transfected cells by immunofluorescence. We found that N-terminus deleted but not wild-type/C-terminus deleted mutant proteins showed a significant number of cytoplasmic, multi-cellular stains in transfected Vero cells. The effect was greatly intensified by subjecting cells to heat shock at 43 degrees C, whereas it was obstructed by treatment with the microfilament-disrupting drug cytochalasin D. The staining patterns of UL14 antigen-positive cells after heat shock suggested a cell-to-cell spread of the protein. Although the mechanism is unclear, the phenomenon seems to be an unprecedented type of intercellular trafficking.     

Influence of Humidity on Ethylene-Induced Internodal Elongation in Floating Rice

When sections of floating rice stems were treated with 1-aminocyclopropane-l-carboxylicacid (ACC) at 60% relative humidity, their ethylene contentincreased but internodes hardly elongated. The internodal elongationinduced by ethylene was promoted in sections incubated at 100%relative humidity but not at 20%. Thus, ethylene-induced internodalelongation in floating rice requires moist surroundings. (Received April 25, 1990; Accepted December 22, 1990)     

Isolation and identification of a naturally occurring 7, 8-didemethyl-8-hydroxy-5-deazariboflavin derivative from Mycobacterium avium

A yellow pigment (C₂₄H₂₆N₄PO₁₅Na₃) was isolated from Mycobacterium avium. On the acid hydrolysis the pigment (1 mol) gave L-glutamic acid (1 mol), lactic acid (1 mol) and 7,8-didemethyl-8-hydroxy-5-deazariboflavin-5′-phosphoric acid. The structure of $\text{N-[O-[[5-(8-}\text{hydroxypyrimidol[4,5-b]}\text{quinoline}\text{-10-}\text{yl}\text{-2,4(3H, 10H)-}\text{dione}\text{)-2,3,4-}\text{trihydroxypentyloxy]hydroxyphosphoryl]-}\text{L}\text{-lactyl]-}\text{L}\text{-glutamic acid}$ was proposed for this compound. The compound isolated functions presumably as a new cofactor in a redox system of the bacteria.     

Formation of Adenosine Triphosphate in Isolated Aleurone Particles of Rice Grains

Using isolated aleurone particles of rice grains it was found that ADP was easily transformed to ATP. This reaction is likely explained by either a transphosphorylation of a phosphate group from phytic acid to ADP or a mechanism involving adenylate kinase. The optimum temperature and pH for this reaction were 30°C and 7.8 respectively. The apparent Km for ADP was 4.0 × 10^?4 m. Cyanide arsenate and azide at 10^?3 to 10^?2 m had no effect on the ATP formation, indicating that the formation was not due to oxidative phosphorylation.     

Phase advance of the light-dark cycle perturbs diurnal rhythms of brain-derived neurotrophic factor and neurotrophin-3 protein levels, which reduces synaptophysin-positive presynaptic terminals in the cortex of juvenile rats

In adult rat brains, brain-derived neurotrophic factor (BDNF) rhythmically oscillates according to the light-dark cycle and exhibits unique functions in particular brain regions. However, little is known of this subject in juvenile rats. Here, we examined diurnal variation in BDNF and neurotrophin-3 (NT-3) levels in 14-day-old rats. BDNF levels were high in the dark phase and low in the light phase in a majority of brain regions. In contrast, NT-3 levels demonstrated an inverse phase relationship that was limited to the cerebral neocortex, including the visual cortex, and was most prominent on postnatal day 14. An 8-h phase advance of the light-dark cycle and sleep deprivation induced an increase in BDNF levels and a decrease in NT-3 levels in the neocortex, and the former treatment reduced synaptophysin expression and the numbers of synaptophysin-positive presynaptic terminals in cortical layer IV and caused abnormal BDNF and NT-3 rhythms 1 week after treatment. A similar reduction of synaptophysin expression was observed in the cortices of Bdnf gene-deficient mice and Ca(2+)-dependent activator protein for secretion 2 gene-deficient mice with abnormal free-running rhythm and autistic-like phenotypes. In the latter mice, no diurnal variation in BDNF levels was observed. These results indicate that regular rhythms of BDNF and NT-3 are essential for correct cortical network formation in juvenile rodents.