Showing 4171 - 4180 of 5831 Items
An Arabidopsis serine/threonine kinase homologue with an epidermal growth factor repeat selected in yeast for its specificity for a thylakoid membrane protein
Date: 1992-01-01
Creator: Bruce D. Kohorn, Steven Lane, Tracy A. Smith
Access: Open access
- A number of molecules have recently been described that effect the correct transport and assembly of cytoplasmically synthesized proteins to cellular membranes. To identify proteins that bind or modify other proteins during the process of membrane translocation, we developed a yeast selection scheme that employs the yeast transcriptional activator GAL4. This selection facilitates the isolation of cDNAs that encode proteases and binding proteins for known target peptide sequences. We report the isolation of an Arabidopsis cDNA encoding a polypeptide that can interact with the amino terminus of a light-harvesting chlorophyll a/b-binding protein (LHCP), a cytoplasmically synthesized protein that is integral to the chloroplast thylakoid membrane. The cDNA was selected in yeast from an Arabidopsis expression library for its ability to inhibit a transcriptional activator GAL4-LHCP fusion protein, but not inhibit native GAL4 protein. The LHCP aminoterminal sequences included in the fusion protein are known to regulate LHCP biogenesis and function. The Arabidopsis cDNA encodes a 595-amino acid protein with at least two functional domains, one with similarity to the family of proteinserine/threonine kinases and another that contains an epidermal growth factor repeat. The identification of an EGF repeat in Arabidopsis indicates that the motif is conserved between the plant and animal kingdoms. Hybridization studies indicate that this gene is likely to be present in other genera of plants. Its mRNA is detected in green leaves but not in other plant tissues or in etiolated plants. The specificity in yeast and the expression pattern in plants together are suggestive of a role for this protein kinase in the assembly or regulation of LHCP.
Determination of the Relationship Between Peptoid Catalyst Oligomeric Length and Catalytic Enantioselectivity of Trifluoromethylation of Aldehydes Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2025-06-01
Date: 2020-01-01
Creator: Katharine Toll
Access: Access restricted to the Bowdoin Community
Combinatorial properties of Thompson's group F
Date: 2004-07-01
Creator: Sean Cleary, Jennifer Taback
Access: Open access
- We study some combinatorial consequences of Blake Fordham's theorems on the word metric of Thompson's group F in the standard two generator presentation. We explore connections between the tree pair diagram representing an element w of F, its normal form in the infinite presentation, its word length, and minimal length representatives of it. We estimate word length in terms of the number and type of carets in the tree pair diagram and show sharpness of those estimates. In addition we explore some properties of the Cayley graph of F with respect to the two generator finite presentation. Namely, we exhibit the form of "dead end" elements in this Cayley graph, and show that it has no "deep pockets". Finally, we discuss a simple method for constructing minimal length representatives for strictly positive or negative words.
Role of SR-like RNA-binding protein 1 (Slr1) in hyphal tip localization of She3-transported mRNA in Candida albicans This record is embargoed.
- Embargo End Date: 2025-05-13
Date: 2020-01-01
Creator: Emma Beane
Access: Embargoed
Consequences of toxic secondary compounds in nectar for mutualist bees and antagonist butterflies
Date: 2016-10-01
Creator: Patricia L. Jones, Anurag A. Agrawal
Access: Open access
- Attraction of mutualists and defense against antagonists are critical challenges for most organisms and can be especially acute for plants with pollinating and non-pollinating flower visitors. Secondary compounds in flowers have been hypothesized to adaptively mediate attraction of mutualists and defense against antagonists, but this hypothesis has rarely been tested. The tissues of milkweeds (Asclepias spp.) contain toxic cardenolides that have long been studied as chemical defenses against herbivores. Milkweed nectar also contains cardenolides, and we have examined the impact of manipulating cardenolides in nectar on the foraging choices of two flower visitors: generalist bumble bees, Bombus impatiens, which are mutualistic pollinators, and specialist monarch butterflies, Danaus plexippus, which are herbivores as larvae and ineffective pollinators as adults. Although individual bumble bees in single foraging bouts showed no avoidance of cardenolides at the highest natural concentrations reported for milkweeds, a pattern of deterrence did arise when entire colonies were allowed to forage for several days. Monarch butterflies were not deterred by the presence of cardenolides in nectar when foraging from flowers, but laid fewer eggs on plants paired with cardenolide-laced flowers compared to controls. Thus, although deterrence of bumble bees by cardenolides may only occur after extensive foraging, a primary effect of nectar cardenolides appears to be reduction of monarch butterfly oviposition.
Bowdoin College - Medical School of Maine Catalogue (1911-1912)
Date: 1912-01-01
Access: Open access
- Bowdoin College Bulletin no. 37
Bowdoin College Catalogue (1914-1915)
Date: 1915-01-01
Access: Open access
- Bowdoin College Bulletin no. 56