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Park S.,University of Minnesota | Park S.,Joint Center for Biosciences | Ozga J.A.,University of Alberta | Cohen J.D.,University of Minnesota | Reinecke D.M.,University of Alberta
Journal of Plant Growth Regulation | Year: 2010

The auxins 4-chloroindole-3-acetic acid (4-Cl-IAA) and indole-3-acetic acid (IAA) occur naturally in pea vegetative and fruit tissues (Pisum sativum L.). Previous work has shown that 4-Cl-IAA can substitute for the seeds in the stimulation of pea pericarp growth, whereas IAA is ineffective. Both auxins are found as free acids and as low-molecular-weight conjugates from organic solvent-soluble extracts from pea fruit. Here we present evidence for an additional conjugated auxin species that was not soluble in organic solvent and yielded 4-Cl-IAA and IAA after strong alkaline hydrolysis, suggestive of auxin attachment to pea seed and pericarp proteins. The solvent-insoluble conjugated 4-Cl-IAA in young pericarp was on average 15-fold greater than solvent-soluble 4-Cl-IAA. The solvent-insoluble conjugated IAA was approximately half the levels reported for the solvent-soluble IAA fraction. To identify putative 4-Cl-IAA-bound proteins, polyclonal antibodies were raised to 4-Cl-IAA linked to bovine serum albumin protein (BSA). Immunoblots probed with anti-4-Cl-IAA-BSA antiserum detected three to four unique bands (32-40 kDa) in primarily maternal tissues, and a different set of protein bands were detected in mainly embryonic tissues (ca. 65-74 kDa in mature seed). 4-Cl-IAA and IAA were also identified from protein fractions separated by polyacrylamide gel electrophoresis using GC-MS. These data show that the majority of 4-Cl-IAA, the growth-active auxin in young pea pericarp, and significant levels of IAA are linked to protein fractions. Auxin-proteins may function in regulation of free bioactive 4-Cl-IAA and IAA levels, and/or 4-Cl-IAA or IAA may be targeted to specific proteins post-translationally to modify protein function or stability. © Springer Science+Business Media, LLC 2009. Source


Yang Z.,University of Rochester | Yang Z.,Joint Center for Biosciences | Hayes J.J.,University of Rochester
Biochemistry | Year: 2011

We previously reported that reconstituted nucleosomes undergo sequence-dependent translational repositioning upon removal of the core histone tail domains under physiological conditions, indicating that the tails influence the choice of position. We report here that removal of the core histone tail domains increases the exposure of the DNA backbone in nucleosomes to hydroxyl radicals, a nonbiased chemical cleavage reagent, indicative of an increase in the motility of the DNA on the histone surface. Moreover, we demonstrate that the divalent cations Mg 2+ and Ca 2+ can replace the role of the tail domains with regard to stabilization of histone-DNA interactions within the nucleosome core and restrict repositioning of nucleosomes upon tail removal. However, when nucleosomes were incubated with Mg 2+ after tail removal, the original distribution of translational positions was not re-established, indicating that divalent cations increase the energy barrier between translational positions rather than altering the free energy differences between positions. Interestingly, other divalent cations such as Zn 2+, Fe 2+, Co 2+, and Mn 2+ had little or no effect on the stability of histone-DNA interactions within tailless nucleosomes. These results support the idea that specific binding sites for Mg 2+ and Ca 2+ ions exist within the nucleosome and play a critical role in nucleosome stability that is partially redundant with the core histone tail domains. © 2011 American Chemical Society. Source


Patent
Joint Center For Biosciences and Salk Institute for Biological Studies | Date: 2012-09-05

Provided herein are methods and compositions for efficient accumulation of structural information (e.g., three dimensional structural information) for amino acid sequences.


Patent
Salk Institute for Biological Studies and Joint Center For Biosciences | Date: 2010-02-24

The present disclosure relates to chimeric polypeptide having TGF-beta activity, nucleic acids encoding the polypeptides, and host cells for producing the polypeptides.


Patent
Salk Institute for Biological Studies and Joint Center For Biosciences | Date: 2014-12-30

The present disclosure relates to chimeric polypeptide having TGF-beta activity, nucleic acids encoding the polypeptides, and host cells for producing the polypeptides.

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