Satoshi Tsuji | PubMed Health

PubMed2004

Physical and functional interactions between STAP-2/BKS and STAT5.

Signal-transducing adaptor protein family of proteins (STAPs), which currently contains two members, are proposed to be adaptor molecules because of their pleckstrin homology (PH) and Src-homology 2 (SH2)-like domains. STAP-1 has been shown to interact with STAT5 and the tyrosine kinase Tec. With regard to STAP-2/BKS functions, immunoprecipitation experiments and intracellular stainings revealed STAP-2/BKS binds STAT5 in several types of cells. Mutational studies revealed that the PH- and SH2-like domains of STAP-2/BKS interacted with the C-terminal region of STAT5. STAP-2/BKS and STAT5 were found to constitutively co-localize in the cytoplasm of resting cells, but STAP-2/BKS was found to dissociate upon STAT5 phosphorylation, suggesting a role in regulating signaling of STAT5. The physiological role of these interactions is not fully understood, but in studies of overexpression of STAP-2/BKS, cytokine-induced tyrosine phosphorylation and transcriptional activation of STAT5 was diminished. In addition, thymocytes from STAP-2/BKS-deficient mice showed the enhanced interleukin-2-dependent cell growth. Taken together, STAP-2/BKS is an additional modulator of STAT5-mediated signaling.

Adaptor Proteins, Signal Transducing↗

PubMed2004

Application of focused ion beam techniques and transmission electron microscopy to thin-film transistor failure analysis.

The locations of process-induced defects in hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), which are used as elements of active-matrix liquid crystal displays, were investigated by combining focused ion beam techniques with cross-sectional transmission electron microscopy (X-TEM). The FIB technique is applied to TFT failure analysis problems, which require considerable localised etching without inducing mechanical stress or damage at fragile failure locations. We demonstrate the manner in which these techniques are used to characterise TFT defects such as pinholes and portions of the multilayer damaged by mechanical stress. A dramatic improvement brought about by the FIB technique is the increase in temporal efficiency of sample preparations. X-TEM observations also lead to identification of the fault and analysis of its cause, which in turn lead to a marked yield improvement.

Equipment Failure↗