Expression pattern of the Brachyury gene in the arrow worm paraspadella gotoi (chaetognatha)

Arrow worms (the phylum Chaetognatha), which are among the major marine planktonic animals, are direct developers and exhibit features characteristic of both deuterostomes and protostomes. In particular, the embryonic development of arrow worms appears to be of the deuterostome type. Brachyury functions critically in the formation of the notochord in chordates, whereas the gene is expressed in both the blastopore and stomodeum invagination regions in embryos of hemichordates and echinoderms. Here we analyzed the expression of Brachyury (Pg-Bra) in the arrow worm Paraspadella gotoi and showed that Pg-Bra is expressed in the blastopore region and the stomodeum region in the embryo and then around the mouth opening region at the time of hatching. The expression of Pg-Bra in the embryo resembles that of Brachyury in embryos of hemichordates and echinoderms, whereas that in the mouth opening region in the hatchling appears to be novel.     

Expression of Apc2 during mouse development

APC2 (previously known as APCL), a molecule closely related to the adenomatous polyposis coli (APC) tumor suppressor, can deplete cytoplasmic beta-catenin, like APC itself. Recently, it has been shown that APC2 may regulate the localization of p53 and the microtubule stability and/or extension. Although it has been reported that APC2 mRNA is expressed in human brain, the anatomical and ontogenic expression patterns remain unclear. The purpose of this study was to investigate the distribution of mouse Apc2 during mouse development. In the adult brain, Apc2 is expressed predominantly in neurons and throughout the brain. Northern blot analysis demonstrated a high level of Apc2 expression in embryonic and early postnatal brain. Ontogenic analysis has indicated that Apc2 is expressed in neural tissue, including the peripheral nervous system. During development of cortex, retina and cerebellum, Apc2 is expressed in post-mitotic cells. These findings suggest that Apc2 may contribute to the development of neuronal cells.     

Phosphorylation of CPI17 and myosin binding subunit of type 1 protein phosphatase by p21-activated kinase

CPI17 and myosin binding subunit of type 1 protein phosphatase (MBS) are the regulators of myosin light chain phosphatase (MLCP). The function of both regulators is controlled by phosphorylation. The phosphorylation of CPI17 at Thr38 significantly enhances the inhibitory activity of CPI17 and the phosphorylation at Thr641 of MBS decreases the MLCP activity. Here, we found that p21-activated protein kinase (PAK) phosphorylates both CPI17 at Thr38 and MBS at Thr641. For CPI17, PAK specifically phosphorylated at Thr38, since the mutation of Thr38 to Ala completely abolished the phosphorylation. On the other hand, PAK phosphorylated Thr641 but not Thr799 of MBS, the site phosphorylated by Rho kinase. Because PAK phosphorylates MBS more than 1 mol/mol, it is anticipated that PAK also phosphorylates other sites in addition to Thr641. CPI17 phosphorylation induced by PAK significantly enhanced the inhibitory activity of CPI17. On the other hand, the phosphorylation of MBS by PAK also decreased the MLCP activity. These results raise the possibility that the PAK pathway plays a role in MLCP regulation.     

Phosphorylation of Fanconi anemia protein, FANCA, is regulated by Akt kinase

Phosphorylation of the Fanconi anemia complementation group A (FANCA) protein is thought to be important for the function of the FA pathway. However, the kinase for FANCA (so-called FANCA-PK) remains to be identified. FANCA has a consensus sequence for Akt kinase near serine 1149 (Ser1149), suggesting that Akt can phosphorylate FANCA. We performed in vitro kinase assays using as substrate either a GST-fusion wild-type (WT) FANCA fragment or a GST-fusion FANCA fragment containing a mutation from serine to alanine at 1149 (FANCA-S1149A). These experiments confirmed that FANCA is phosphorylated at Ser 1149, in vitro. However, (32)P-orthophosphate labeling experiments revealed that FANCA-S1149A was more efficiently phosphorylated than WT-FANCA. Furthermore, phosphorylation of wild-type FANCA was blocked by coexpression of a constitutively active (CA)-Akt and enhanced by a dominant-negative (DN) Akt. Our results suggest that Akt is a negative regulator of FANCA phosphorylation.     

Characterization of Epstein-Barr virus (EBV)-positive NK cells isolated from hydroa vacciniforme-like eruptions

Recently, the involvement of Epstein-Barr virus (EBV) in hydroa vacciniforme (HV)-like eruptions has been suggested. To elucidate the role of EBV in this disease, we isolated EBV-infected cell clones from peripheral blood mononuclear cells (PBMC) and the skin lesions of a patient with HV-like eruptions; cells isolated from PBMC were designated SNK-12, and those from the eruption SNK-11. Both cells expressed CD16, CD56, and HLA-DR and had germline configurations of the T-cell receptor and the immunoglobulin genes, indicating that the cell clones were of NK cell lineage. The analysis of EBV terminal repeats indicated that the cells were monoclonal, had identical clonality, and originated from EBV-positive cells in the PBMC and eruption. Both clones expressed EBNA-1, but not EBNA-2. Although LMP-1 was weakly detected in SNK-11, no LMP-1 was detected in SNK-12. Interestingly, EBV-infected cells required less IL-2 for in vitro growth in the later phase of this disease and this appeared to correlate with the expression of LMP-1, suggesting that the proliferative capacity of the EBV-positive NK cells increased during the time course of the disease, and LMP-1 expression might be responsible for that. This is the first report of the isolation of EBV-infected cells from the skin lesions of HV-like eruptions and strongly suggests that the HV-like eruption in the patient was caused by clonal NK cells with latent EBV infection.