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Canola ( Brassica napus), an agriculturally important oilseed crop, can be significantly affected by diseases such as sclerotinia stem rot, blackleg, and alternaria black spot resulting in significant loss of crop productivity and quality. Cysteine-rich antimicrobial peptides isolated from plants have emerged as a potential resource for protection of plants against phytopathogens. Here we report the significance of an antimicrobial peptide, PmAMP1, isolated from western white pine ( Pinus monticola), in providing canola with resistance against multiple phytopathogenic fungi. The cDNA encoding PmAMP1 was successfully incorporated into the genome of B. napus, and it's in planta expression conferred greater protection against Alternaria brassicae, Leptosphaeria maculans and Sclerotinia sclerotiorum. In vitro experiments with proteins extracted from transgenic canola expressing Pm-AMP1 demonstrated its inhibitory activity by reducing growth of fungal hyphae. In addition, the in vitro synthesized peptide also inhibited the growth of the fungi. These results demonstrate that generating transgenic crops expressing PmAMP1 may be an effective and versatile method to protect susceptible crops against multiple phytopathogens. [ABSTRACT FROM AUTHOR]

Abstract: The family of cysteine rich proteins (CRP) comprises three closely homologous members that have been reported to interact with α-actinin. Muscular LIM protein (MLP/CRP3), the skeletal muscle variant, was originally discovered as a positive regulator of myogenesis and is suggested to be part of the stretch sensor of the myofibril through its interaction with telethonin (T-Cap). We determined the structure of both LIM domains of human MLP by nuclear magnetic resonance spectroscopy. We confirm by 15N relaxation measurements that both LIM domains act as independent units and that the adjacent linker regions are fully flexible. With the published structures of CRP1 and CRP2, the complete family has now been structurally characterized. [Copyright &y& Elsevier]

In the past decades, the major focus of antigen variation research has been on parasitic protists. However, antigenic variation occurs also in free-living protists. The antigenic systems of the ciliates Paramecium and Tetrahymena have been studied for more than 100 yr. In spite of different life strategies and distant phylogenetic relationships of free-living ciliates and parasitic protists, their antigenic systems have features in common, such as the presence of repeated protein motifs and multigene families. The function of variable surface antigens in free-living ciliates is still unknown. Up to now no detailed monitoring of antigen expression in free-living ciliates in natural habitats has been performed. Unlike stochastic switching in parasites, antigen expression in ciliates can be directed, e.g. by temperature, which holds great advantages for research on the expression mechanism. Regulated expression of surface antigens occurs in an exclusive way and the responsible mechanism is complex, involving both transcriptional and post-transcriptional features. The involvement of homology-dependent effects has been proposed several times but has not been proved yet. [ABSTRACT FROM AUTHOR]