Identification of a family of zinc transporter genes from Arabidopsis that respond to zinc deficiency

Millions of people worldwide suffer from nutritional imbalances of essential metals like zinc. These same metals, along with pollutants like cadmium and lead, contaminate soils at many sites around the world. In addition to posing a threat to human health, these metals can poison plants, livestock, and wildlife. Deciphering how metals are absorbed, transported, and incorporated as protein cofactors may help solve both of these problems. For example, edible plants could be engineered to serve as better dietary sources of metal nutrients, and other plant species could be tailored to remove metal ions from contaminated soils. We report here the cloning of the first zinc transporter genes from plants, the ZIP1, ZIP2, and ZIP3 genes of Arabidopsis thaliana. Expression in yeast of these closely related genes confers zinc uptake activities. In the plant, ZIP1 and ZIP3 are expressed in roots in response to zinc deficiency, suggesting that they transport zinc from the soil into the plant. Although expression of ZIP2 has not been detected, a fourth related Arabidopsis gene identified by genome sequencing, ZIP4, is induced in both shoots and roots of zinc-limited plants. Thus, ZIP4 may transport zinc intracellularly or between plant tissues. These ZIP proteins define a family of metal ion transporters that are found in plants, protozoa, fungi, invertebrates, and vertebrates, making it now possible to address questions of metal ion accumulation and homeostasis in diverse organisms.

Serine and Threonine Phosphorylation of the Paxillin LIM Domains Regulates Paxillin Focal Adhesion Localization and Cell Adhesion to Fibronectin

We have previously shown that the LIM domains of paxillin operate as the focal adhesion (FA)-targeting motif of this protein. In the current study, we have identified the capacity of paxillin LIM2 and LIM3 to serve as binding sites for, and substrates of serine/threonine kinases. The activities of the LIM2- and LIM3-associated kinases were stimulated after adhesion of CHO.K1 cells to fibronectin; consequently, a role for LIM domain phosphorylation in regulating the subcellular localization of paxillin after adhesion to fibronectin was investigated. An avian paxillin-CHO.K1 model system was used to explore the role of paxillin phosphorylation in paxillin localization to FAs. We found that mutations of paxillin that mimicked LIM domain phosphorylation accelerated fibronectin-induced localization of paxillin to focal contacts. Further, blocking phosphorylation of the LIM domains reduced cell adhesion to fibronectin, whereas constitutive LIM domain phosphorylation significantly increased the capacity of cells to adhere to fibronectin. The potentiation of FA targeting and cell adhesion to fibronectin was specific to LIM domain phosphorylation as mutation of the amino-terminal tyrosine and serine residues of paxillin that are phosphorylated in response to fibronectin adhesion had no effect on the rate of FA localization or cell adhesion. This represents the first demonstration of the regulation of protein localization through LIM domain phosphorylation and suggests a novel mechanism of regulating LIM domain function. Additionally, these results provide the first evidence that paxillin contributes to “inside-out” integrin-mediated signal transduction.

Customizing for clients: developing a library liaison program from need to plan*

Building on the experiences of librarian representatives to curriculum committees in the colleges of dentistry, medicine, and nursing, the Health Science Center Libraries (HSCL) Strategic Plan recommended the formation of a Library Liaison Work Group to create a formal Library Liaison Program to serve the six Health Science Center (HSC) colleges and several affiliated centers and institutes. The work group's charge was to define the purpose and scope of the program, identify models of best practice, and recommend activities for liaisons. The work group gathered background information, performed an environmental scan, and developed a philosophy statement, a program of liaison activities focusing on seven |primary areas, and a forum for liaison communication. Hallmarks of the plan included intensive subject specialization (beyond collection development), extensive communication with users, and personal information services. Specialization was expected to promote competence, communication, confidence, comfort, and customization. Development of the program required close coordination with other strategic plan implementation teams, including teams for collection development, education, and marketing. This paper discusses the HSCL's planning process and the resulting Library Liaison Program. Although focusing on an academic health center, the planning process and liaison model may be applied to any library serving diverse, subject-specific user populations.

Building a retrospective collection in pharmacy: a brief history of the literature with some considerations for U.S. health sciences library professionals

This paper argues that historical works in pharmacy are important tools for the clinician as well as the historian. With this as its operative premise, delineating the tripartite aspects of pharmacy as a business enterprise, a science, and a profession provides a conceptual framework for primary and secondary resource collecting. A brief history and guide to those materials most essential to a historical collection in pharmacy follows. Issues such as availability and cost are discussed and summarized in checklist form. In addition, a glossary of important terms is provided as well as a list of all the major U.S. dispensatories and their various editions. This paper is intended to serve as a resource for those interested in collecting historical materials in pharmacy and pharmaco-therapeutics as well as provide a history that gives context to these classics in the field. This should provide a rationale for selective retrospective collection development in pharmacy.

A medical book collection for physician assistants

Selecting resources for physician assistants is challenging and can be overwhelming. Although several core lists exist for nursing, allied health, and medical libraries, judging the scope and level of these resources in relation to the information needs of the physician assistant is difficult. Medical texts can be highly specialized and very expensive, in essence, “overkill” for the needs of the physician assistant. This bibliography is meant to serve as a guide to appropriate medical texts for physician assistants. Titles were selected from the Brandon/Hill list, Doody's Electronic Journal, and various other reference resources. Resources were evaluated based on the subject and scope, audience, authorship, cost, and currency. The collection includes 195 titles from 33 specialty areas. Standard texts in each area are also included.

An automated multiplex oligonucleotide synthesizer: development of high-throughput, low-cost DNA synthesis.

An automated oligonucleotide synthesizer has been developed that can simultaneously and rapidly synthesize up to 96 different oligonucleotides in a 96-well microtiter format using phosphoramidite synthesis chemistry. A modified 96-well plate is positioned under reagent valve banks, and appropriate reagents are delivered into individual wells containing the growing oligonucleotide chain, which is bound to a solid support. Each well has a filter bottom that enables the removal of spent reagents while retaining the solid support matrix. A seal design is employed to control synthesis environment and the entire instrument is automated via computer control. Synthesis cycle times for 96 couplings are < 11 min, allowing a plate of 96 20-mers to be synthesized in < 5 hr. Oligonucleotide synthesis quality is comparable to commercial machines, with average coupling efficiencies routinely > 98% across the entire 96-well plate. No significant well-to-well variations in synthesis quality have been observed in > 6000 oligonucleotides synthesized to date. The reduced reagent usage and increased capacity allow the overall synthesis cost to drop by at least a factor of 10. With the development of this instrument, it is now practical and cost-effective to synthesize thousands to tens of thousands of oligonucleotides.