Collagen, the major extracellular matrix protein, is also a membrane protein. Two types of collagen are detected on the normal human fibroblast membrane in culture, type I collagen and a new immunologically and chemically distinct collagen, type M (membrane) collagen. Antibodies to type M collagen elicited complement-mediated cytotoxicity, which could be blocked by pretreatment of the cells with bacterial collagenase or the antibody with type M collagen. Pretreatment of the cells with other proteolytic enzymes or the antibody with type I collagen or type III collagen had no effect on this complement-mediated cytotoxicity. Although type I collagen is the major collagen synthesized by normal human fibroblasts type M collagen may be the major cell membrane collagen and may be a major cell membrane component.
Abstract Cytokine-induced tyrosine phosphorylation of the transcription factor STAT5 is required for its transcriptional activity. In this article we show that the small dual-specificity phosphatase VHR selectively dephosphorylates IFN-α- and β-activated, tyrosine-phosphorylated STAT5, leading to the subsequent inhibition of STAT5 function. Phosphorylation of VHR at Tyr138 was required for its phosphatase activity toward STAT5. In addition, the Src homology 2 domain of STAT5 was required for the effective dephosphorylation of STAT5 by VHR. The tyrosine kinase Tyk2, which mediates the phosphorylation of STAT5, was also responsible for the phosphorylation of VHR at Tyr138.
Problem solving, data collection, and analysis in geology require diverse tools and methods. Computers must be convenient and versatile to be useful as laboratory apparatus and as tools for use in formation evaluation and geologic interpretation. Networking and distributed intelligence provide a laboratory with flexibility and power for cost-effective real-time data collection, management, and analysis. Networking facilities toolbox-style programming; improves data compilation, management, and comparison; and increases peripheral effectiveness. Distributed intelligence enhances local instrumentation, uninterrupted real-time data collector, and data analysis. The system presented includes facilities for instrumentation, data collection and management, and interpretation, analysis, and presentation for such systems as mercury injection, rock electrical properties, gas slippage, Klinkenberg correction, gamma-ray logging, cation exchange capacity, thermal neutron capture cross section, and permeability/porosity measurements. The individual systems share central text and graphic hard-copy devices and high-speed mass storage and backup facilities. Modifying the central system updates many of the remote system facilities such as user interfaces and graphic facilities. Individual system configurations include instrumentation, high-resolution color graphics, analog to digital conversion, and variation in computing power.
