Bio-photosensor: Cyanobacterial photosystem I coupled with transistor via molecular wire

We report on the first successful output of electrons directly from photosystem I (PSI) of thermophilic cyanobacteria to the gate of a field-effect transistor (FET) by bypassing electron flow via a newly designed molecular wire, i.e., artificial vitamin K(1), and a gold nanoparticle; in short, this newly manufactured photosensor employs a bio-functional unit as the core of the device. Photo-electrons generated by the irradiation of molecular complexes composed of reconstituted PSI on the gate were found to control the FET. This PSI-bio-photosensor can be used to interpret gradation in images. This PSI-FET system is moreover sufficiently stable for use exceeding a period of 1 year.     

Drosophila beta 1,4-N-acetylgalactosaminyltransferase-A synthesizes the LacdiNAc structures on several glycoproteins and glycosphingolipids

The GalNAcbeta1,4GlcNAc (LacdiNAc or LDN) structure is a more common structural feature in invertebrate glycoconjugates when compared with the Galbeta1,4GlcNAc structure. Recently, beta1,4-N-acetylgalactosaminyltransferase (beta4GalNAcT) was identified in some invertebrates including Drosophila. However, the LDN structure has not been reported in Drosophila, and the biological function of LDN remains to be determined. In this study, we examined acceptor substrate specificity of Drosophila beta4GalNAcTA by using some N- and O-glycans on glycoproteins and neutral glycosphingolipids (GSLs). GalNAc was efficiently transferred toward N-glycans, O-glycans, and the arthro-series GSLs. Moreover, we showed that dbeta4GalNAcTA contributed to the synthesis of the LDN structure in vivo. The dbeta4GalNAcTA mRNA was highly expressed in the developmental and adult neuronal tissues. Thus, these results suggest that dbeta4GalNAcTA acts on the terminal GlcNAc residue of some glycans for the synthesis of LDN, and the LDN structure may play a role in the physiological or neuronal development of Drosophila.     

Bio-photosensor: Cyanobacterial photosystem I coupled with transistor via molecular wire

We report on the first successful output of electrons directly from photosystem I (PSI) of thermophilic cyanobacteria to the gate of a field-effect transistor (FET) by bypassing electron flow via a newly designed molecular wire, i.e., artificial vitamin K₁, and a gold nanoparticle; in short, this newly manufactured photosensor employs a bio-functional unit as the core of the device. Photo-electrons generated by the irradiation of molecular complexes composed of reconstituted PSI on the gate were found to control the FET. This PSI-bio-photosensor can be used to interpret gradation in images. This PSI-FET system is moreover sufficiently stable for use exceeding a period of 1 year.     

sn-Glycerol-1-Phosphate-Forming Activities in Archaea: Separation of Archaeal Phospholipid Biosynthesis and Glycerol Catabolism by Glycerophosphate Enantiomers

In Methanobacterium thermoautotrophicum, sn-glycerol-1-phosphate (G-1-P) dehydrogenase is responsible for the formation of the Archaea-specific backbone of phospholipids, G-1-P, from dihydroxyacetonephosphate (DHAP). The possible G-1-P-forming activities were surveyed in cell-free extracts of six species of Archaea. All the archaeal cell-free homogenates tested revealed the ability to form G-1-P from DHAP. In addition, activities of G-3-P-forming glycerol kinase and G-3-P dehydrogenase were also detected in four heterotrophic archaea, while glycerol kinase activity was not detected in two autotrophic methanogens. These results show that G-1-P is produced from DHAP by G-1-P dehydrogenase in a wide variety of archaea while exogenous glycerol is catabolized via G-3-P.     

Expression of stromal cell-derived factor-1/pre-B cell growth-stimulating factor receptor, CXC chemokine receptor 4, on CD34+ human bone marrow cells is a phenotypic alteration for committed lymphoid progenitors.

We found that the stromal cell-derived factor-1/pre-B cell growth-stimulating factor receptor, CXC chemokine receptor 4 (CXCR4), is expressed on human CD34+ bone marrow (BM) cells. Stringently FACS-sorted CD34+CXCR4+ BM cells completely lack myeloid, erythroid, megakaryocytic, and mixed colony-forming potential (myeloid progenitors), but give rise to B and T lymphoid progenitors, whereas CD34+CXCR4- BM cells can generate colonies formed by myeloid progenitors and can also develop into these lymphoid progenitors. Therefore, expression of CXCR4 on CD34+ BM cells can allow lymphoid progenitors to be discriminated from myeloid progenitors. Because CD34+CXCR4+ cells are differentiated from CD34+CXCR4- cells, multipotential progenitors located in the BM are likely to be negative for CXCR4 expression. CXCR4 seems to be expressed earlier than the IL-7R and terminal deoxynucleotidyl transferase during early lymphohemopoiesis. These results suggest that the expression of CXCR4 on CD34+ BM cells is one of the phenotypic alterations for committed lymphoid progenitors.     

Osteoclast differentiation factor acts as a multifunctional regulator in murine osteoclast differentiation and function.

Osteoclast differentiation factor (ODF), a novel member of the TNF ligand family, is expressed as a membrane-associated protein by osteoblasts/stromal cells. The soluble form of ODF (sODF) induces the differentiation of osteoclast precursors into osteoclasts in the presence of M-CSF. Here, the effects of sODF on the survival, multinucleation, and pit-forming activity of murine osteoclasts were examined in comparison with those of M-CSF and IL-1. Osteoclast-like cells (OCLs) formed in cocultures of murine osteoblasts and bone marrow cells expressed mRNA of RANK (receptor activator of NF-kappaB), a receptor of ODF. The survival of OCLs was enhanced by the addition of each of sODF, M-CSF, and IL-1. sODF, as well as IL-1, activated NF-kappaB and c-Jun N-terminal protein kinase (JNK) in OCLs. Like M-CSF and IL-1, sODF stimulated the survival and multinucleation of prefusion osteoclasts (pOCs) isolated from the coculture. When pOCs were cultured on dentine slices, resorption pits were formed on the slices in the presence of either sODF or IL-1 but not in that of M-CSF. A soluble form of RANK as well as osteoprotegerin/osteoclastogenesis inhibitory factor, a decoy receptor of ODF, blocked OCL formation and prevented the survival, multinucleation, and pit-forming activity of pOCs induced by sODF. These results suggest that ODF regulates not only osteoclast differentiation but also osteoclast function in mice through the receptor RANK.