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Abstract Fibrillin microfibrils are extensible polymers that endow connective tissues with long-range elasticity and have widespread distributions in both elastic and non-elastic tissues. They act as a template for elastin deposition during elastic fibre formation and are essential for maintaining the integrity of tissues such as blood vessels, lung, skin and ocular ligaments. A reduction in fibrillin is seen in tissues in vascular ageing, chronic obstructive pulmonary disease, skin ageing and UV induced skin damage, and age-related vision deterioration. Most mutations in fibrillin cause Marfan syndrome, a genetic disease characterised by overgrowth of the long bones and other skeletal abnormalities with cardiovascular and eye defects. However, mutations in fibrillin and fibrillin-binding proteins can also cause short-stature pathologies. All of these diseases have been linked to dysregulated growth factor signalling which forms a major functional role for fibrillin. [ABSTRACT FROM AUTHOR]

The ability of the plasmid pTF-FC2 to transfer genes into plants was investigated. Using this plasmid as the backbone two plasmids were constructed namely pTD1 and pDER-bar. These plasmids contained, as plant selectable markers, the nptII and the bar genes, respectively. The nptII gene was flanked by the right and left borders and the bar gene was not. Transgenic plants were obtained through the co-cultivation of tobacco leaf discs with the Agrobacterium tumefaciens strain LBA4404(pAL4404)(pDER-bar). Molecular and genetic analysis indicated that the bar gene had been stably integrated into the plant genome and had been inherited in a Mendelian fashion. Integration was shown to be polar and unidirectional and in some cases the entire plasmid was found to have integrated into the plant genome. Interestingly, no plants were generated from tobacco leaf discs that were co-cultivated with the strain C58C1(pMP90)(pTD1). [Copyright &y& Elsevier]

Abstract: The plant nucleus is an important subcellular organelle but the isolation of pure and enriched nuclei from plants and subsequent extraction of nuclear proteins for proteomic studies is challenging. Here, we present protocols for nuclei isolation and nuclear protein extraction from the resurrection plant, Xerophyta viscosa, and show optimization and modification of the most critical steps. [Copyright &y& Elsevier]

Elastic fibres are essential components of all mammalian elastic tissues such as blood vessels, lung and skin, and are critically important for the mechanical properties they endow. The main components of elastic fibres are elastin and fibrillin, where correct formation of elastic fibres requires a fibrillin microfibril scaffold for the deposition of elastin. It has been demonstrated previously that the interaction between fibrillin and tropoelastin, the elastin precursor, increases the rate of assembly of tropoelastin. Furthermore, tropoelastin and fibrillin can be cross-linked by transglutaminase-2, but the function of cross-linking on their elastic properties is yet to be elucidated. Here we show that transglutaminase cross-linking supports formation of a 1:1 stoichiometric fibrillin–tropoelastin complex. SAXS data show that the complex retains features of the individual proteins but is elongated supporting end-to-end assembly. Elastic network models were constructed to compare the dynamics of tropoelastin and fibrillin individually as well as in the cross-linked complex. Normal mode analysis was performed to determine the structures' most energetically favourable, biologically accessible motions which show that within the complex, tropoelastin is less mobile and this molecular stabilisation extends along the length of the tropoelastin molecule to regions remote from the cross-linking site. Together, these data suggest a long-range stabilising effect of cross-linking that occurs due to the covalent linkage of fibrillin to tropoelastin. This work provides insight into the interactions of tropoelastin and fibrillin and how cross-link formation stabilises the elastin precursor so it is primed for elastic fibre assembly. Unlabelled Image • Elastic fibres, essential for mammalian tissue elasticity, contain elastin and fibrillin. • Tissue transglutaminase cross-links fibrillin and tropoelastin to form a complex. • The complex has an elongated structure that supports end-to-end assembly. • Cross-linking restricts the molecular motions of tropoelastin and fibrillin. • Stabilisation may provide an initiating molecular mechanism for elastic fibre assembly. [ABSTRACT FROM AUTHOR]

Abstract: We used in vivo (biological), in silico (computational structure prediction), and in vitro (model sequence folding) analyses of single-stranded DNA sequences to show that nucleic acid folding conservation is the selective principle behind a high-frequency single-nucleotide reversion observed in a three-nucleotide mutated motif of the Maize streak virus replication associated protein (Rep) gene. In silico and in vitro studies showed that the three-nucleotide mutation adversely affected Rep nucleic acid folding, and that the single-nucleotide reversion [C(601)A] restored wild-type-like folding. In vivo support came from infecting maize with mutant viruses: those with Rep genes containing nucleotide changes predicted to restore a wild-type-like fold [A(601)/G(601)] preferentially accumulated over those predicted to fold differently [C(601)/T(601)], which frequently reverted to A(601) and displaced the original population. We propose that the selection of native nucleic acid folding is an epigenetic effect, which might have broad implications in the evolution of plants and their viruses. [Copyright &y& Elsevier]