Structure and Catalytic Properties of Protein Tyrosine Phosphatases a

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75665/1/j.1749-6632.1995.tb26644.x.pd

A secretory kinase complex regulates extracellular protein phosphorylation.

Although numerous extracellular phosphoproteins have been identified, the protein kinases within the secretory pathway have only recently been discovered, and their regulation is virtually unexplored. Fam20C is the physiological Golgi casein kinase, which phosphorylates many secreted proteins and is critical for proper biomineralization. Fam20A, a Fam20C paralog, is essential for enamel formation, but the biochemical function of Fam20A is unknown. Here we show that Fam20A potentiates Fam20C kinase activity and promotes the phosphorylation of enamel matrix proteins in vitro and in cells. Mechanistically, Fam20A is a pseudokinase that forms a functional complex with Fam20C, and this complex enhances extracellular protein phosphorylation within the secretory pathway. Our findings shed light on the molecular mechanism by which Fam20C and Fam20A collaborate to control enamel formation, and provide the first insight into the regulation of secretory pathway phosphorylation

The Finger Wrecker / words by Bert Dixon

Cover: description reads novelty piano solo; Publisher: Jack Mills Inc. (New York)https://egrove.olemiss.edu/sharris_d/1031/thumbnail.jp

Damping capacity of a model steel structure

The damping capacities of seven model steel structures, each consisting of a heavy steel platform supported on four columns, have been determined from forced vibration tests. The vibrations were produced by an eccentric-mass vibration generator, and the amplitudes ranged from small displacements up to slightly greater than yield displacement. The tests were terminated at the higher amplitudes once fatigue cracks formed in any of the joint welds in the columns. For vibration amplitudes up to a critical amplitude slightly less than yield displacement, the damping factors of the structures were constant, independent of amplitude, and ranged between .15 and .25~ for different structures. At vibration amplitudes greater than the critical amplitude, the damping factors of the structures became functions of amplitude. For example, the damping factor of one test structure increased from .15 to 1.~ as the displacement amplitude increased from 1.1 to 1.4 inches. The last structure tested revealed that a few cycles of vibration at amplitudes greater than the critical amplitude would increase these values slightly. Finally, the results summarized above are compared with the results of: {i) experimental work conducted by Lazan; {ii) reversed loading tests conducted on cantilever beams of similar construction to those tested in the work described in this report; and (iii) experimental work conducted by Hanson

The dynamic behavior of steel frame and truss buildings

This report describes experimental and analytical studies of the dynamic behavior of the East Building of the University of California\u27s new Medical Center at San Francisco, California. It also describes experimental tests conducted on the East Building\u27s mechanical service tower and on an adjacent elevator tower. Experimental tests on the East Building were conducted in the summers of 1964 and 1965. Vibrations were produced by eccentric-masstype vibration generators. Frequency responses, time responses, and mode shapes were observed. In the summer 1964 tests, the first mode east-west had 2% of critical damping and the first mode north-south had 1.8%; the values of damping for the higher modes lay in the range 0.4% to 0.9% of critical In the summer 1965 tests, the damping capacity measurements were mostly in the range 5 to 10% of critical. The cause of this increase in damping capacity was investigated in the fall 1965 tests. The fall 1965 tests showed that although the East Building was designed as free-standing, it was dynamically coupled to its adjacent buildings The relatively large damping capacity of this coupled system has been attributed to the Coulomb damping provided by non-structural connections between buildings An analytical model of the East Building was formulated to provide behavior corresponding to the summer 1964 test results. A standard openframe- type model was found capable of representing the dynamic behavior of the real structure. The analytical model was subjected to the El Centro earthquake ground acceleration record in a digital computer analysis. With 5% critical damping in the first few modes, no members of the frame yielded, but when the intensity of the earthquake was increased by a factor of 1.3, some members did yield

LOFT-1 Mission: New Concepts For Educational and Commercial Spaceflight

The Launch Operations Flight Test One (LOFT-1) was originally conceived by E\u27Prime Aerospace Corporation (EPAC) of Titusville, Florida, as strictly an administrative pathfinder toward satisfying all governmental requirements for conducting commercial spaceflight activities from the Cape Canaveral Air Force Station (CCAFS). As the program progressed from early June 1987 toward the original launch date set in the Fall, the complexion of the flight changed dramatically to one of a bonafide scientific mission. Four individual educational/commercial organizations agreed to provide experiments. As such, LOFT-1 would mark the first launch of a privately developed and funded suborbital vehicle carrying payloads from the CCAFS. The University of Alabama in Huntsville, by way of participants within the Industrial and Systems Engineering Department, volunteered to serve as a focal point for all LOFT-1 payload design and integration tasks. In addition, UAH went on to design and develop its own experiment. Given only a few short months between conception of the mission and the originally planned flight date of October 1^, 1987, it was necessary to define a close-knit team, literally from across the nation, to make the mission possible within the original time constraint

The Steinmann Cluster Bootstrap for N=4 Super Yang-Mills Amplitudes

We review the bootstrap method for constructing six- and seven-particle amplitudes in planar $\mathcal{N}=4$ super Yang-Mills theory, by exploiting their analytic structure. We focus on two recently discovered properties which greatly simplify this construction at symbol and function level, respectively: the extended Steinmann relations, or equivalently cluster adjacency, and the coaction principle. We then demonstrate their power in determining the six-particle amplitude through six and seven loops in the NMHV and MHV sectors respectively, as well as the symbol of the NMHV seven-particle amplitude to four loops.Comment: 36 pages, 4 figures, 5 tables, 1 ancillary file. Contribution to the proceedings of the Corfu Summer Institute 2019 "School and Workshops on Elementary Particle Physics and Gravity" (CORFU2019), 31 August - 25 September 2019, Corfu, Greec

Naturalness Versus Supersymmetric Non-renormalization Theorems

We give an intuitive proof of a new non-renormalization theorem in supersymmetric field theories. It applies both perturbatively and non-perturbatively. The superpotential is not renormalized in perturbation theory but receives non-perturbative corrections. However, these non-perturbative corrections are {\it not} generic functions of the fields consistent with the symmetries. Certain invariant terms are not generated. This violation of naturalness has applications to dynamical supersymmetry breaking.Comment: 14 pages, RU-93-4

A Yersinia Effector and a Pseudomonas Avirulence Protein Define a Family of Cysteine Proteases Functioning in Bacterial Pathogenesis

AbstractA Yersinia effector known as YopT and a Pseudomonas avirulence protein known as AvrPphB define a family of 19 proteins involved in bacterial pathogenesis. We show that both YopT and AvrPphB are cysteine proteases, and their proteolytic activities are dependent upon the invariant C/H/D residues conserved in the entire YopT family. YopT cleaves the posttranslationally modified Rho GTPases near their carboxyl termini, releasing them from the membrane. This leads to the disruption of actin cytoskeleton in host cells. The proteolytic activity of AvrPphB is essential for autoproteolytic cleavage of an AvrPphB precursor as well as for eliciting the hypersensitive response in plants. These findings provide new insights into mechanisms of animal and plant pathogenesis