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EF-hand Protein (ef-hand + protein)

Distribution by Scientific Domains

Life Sciences	60%
Chemistry	40%

Selected Abstracts

Expression analysis of genes induced in barley after chemical activation reveals distinct disease resistance pathways

MOLECULAR PLANT PATHOLOGY, Issue 5 2000
Katrin Beßer
Salicylic acid (SA) and its synthetic mimics 2,6-dichloroisonicotinic acid (DCINA) and benzo(1,2,3)thiadiazole-7-carbothioic acid S-methyl ester (BTH), protect barley systemically against powdery mildew (Blumeria graminis f.sp. hordei, Bgh) infection by strengthening plant defence mechanisms that result in effective papillae and host cell death. Here, we describe the differential expression of a number of newly identified barley chemically induced (BCI) genes encoding a lipoxygenase (BCI-1), a thionin (BCI-2), an acid phosphatase (BCI-3), a Ca2+ -binding EF-hand protein (BCI-4), a serine proteinase inhibitor (BCI-7), a fatty acid desaturase (BCI-8) and several further proteins with as yet unknown function. Compared with SA, the chemicals DCINA and BTH were more potent inducers of both gene expression and resistance. Homologues of four BCI genes were detected in wheat and were also differentially regulated upon chemical activation of disease resistance. Except for BCI-4 and BCI-5 (unknown function), the genes were also induced by exogenous application of jasmonates, whereas treatments that raise endogenous jasmonates as well as wounding were less effective. The fact that BCI genes were not expressed during incompatible barley,Bgh interactions governed by gene-for-gene relationships suggests the presence of separate pathways leading to powdery mildew resistance. [source]

Identification of a heat-shock protein Hsp40, DjB1, as an acrosome- and a tail-associated component in rodent spermatozoa

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 2 2007
Masamichi Doiguchi
Abstract Iba1 is a 17-kDa EF-hand protein highly expressed in the cytoplasm of elongating spermatids in testis. Using Iba1 as a bait, we performed yeast Two-hybrid screening and isolated a heat-shock protein Hsp40, DjB1, from cDNA library of mouse testis. To characterize DjB1 that is encoded by Dnajb1 gene, we carried out immunoblot analyses, in situ hybridization, and immunohistochemistry. Immunoblot analyses showed that DjB1was constitutively expressed in mouse testis and that its expression level was not changed by heat shock. Dnajb1 mRNA was exclusively expressed in spermatocytes and round spermatids in mouse testis, and Dnajb1 protein DjB1 was predominantly expressed in the cytoplasm of spermatocytes, round spermatids, and elongating spermatids. In mature mouse spermatozoa, DjB1 was localized in the middle and the end pieces of flagella as well as in association with the head (acrosomal region). Association of DjB1 with the acrosomal region in sperm head was also observed in rat spermatozoa. These data suggested that DjB1, which was constitutively expressed in postmeiotic spermatogenic cells in testis, was integrated into spermatozoa as at least two components, that is, sperm head and tail of rodent spermatozoa. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source]

Crystallization and calcium/sulfur SAD phasing of the human EF-hand protein S100A2

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2010
Michael Koch
Human S100A2 is an EF-hand protein and acts as a major tumour suppressor, binding and activating p53 in a Ca2+ -dependent manner. Ca2+ -bound S100A2 was crystallized and its structure was determined based on the anomalous scattering provided by six S atoms from methionine residues and four calcium ions present in the asymmetric unit. Although the diffraction data were recorded at a wavelength of 0.90,Å, which is usually not assumed to be suitable for calcium/sulfur SAD, the anomalous signal was satisfactory. A nine-atom substructure was determined at 1.8,Å resolution using SHELXD, and SHELXE was used for density modification and phase extension to 1.3,Å resolution. The electron-density map obtained was well interpretable and could be used for automated model building by ARP/wARP. [source]

Calgizarrin like gene (Cal) deficient mice undergo normal spermatogenesis

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 4 2003
Ashraf U. Mannan
Abstract The murine calgizzarin like gene (Cal) encodes for a calcium binding protein, which belongs to the S100 family of EF-hand proteins. It is specifically expressed in Sertoli cells in the testis and its expression is down-regulated by unknown factor(s) from spermatocytes/spermatids. In this paper, we show by transfection of a fusion protein of green fluorescent protein and Cal protein into NIH3T3 cells, that the expression of Cal is restricted only in the cytoplasm of the cell. A differentially regulated cytoplasmic expression of the Cal in Sertoli cells during mouse development suggests that Cal might play an important role during spermatogenesis. In order to elucidate the function of the Cal protein in the spermatogenesis, we disrupted the Cal locus in mouse by homologous recombination. In our knockout mouse, we deleted exon 2 and exon 3 of the Cal gene and replaced them with a neomycin cassette, which resulted in a complete loss of the Cal transcript. Male and female Cal4+/, and Cal4,/, mice from genetic backgrounds C57BL/6J,× 129X1/SvJ hybrid and 129X1/SvJ inbred exhibited normal phenotype and were fertile. An intensive phenotypic analysis showed no gross abnormalities in testis morphology. The lack of the Cal protein also does not affect the parameters of sperm, as they are able to fertilize the oocytes in a competent manner, which is comparable to wild-type sperm. Collectively our results demonstrate that Cal is a nonessential protein and it does not play an important role in mouse spermatogenesis or in process of fertilization. Mol. Reprod. Dev. 66: 431,438, 2003. © 2003 Wiley-Liss, Inc. [source]

Calretinin and calbindin D28k have different domain organizations

PROTEIN SCIENCE, Issue 1 2003
gorzata Palczewska
Abstract The domain organization of calretinin (CR) was predicted to involve all six EF-hand motifs (labeled I to VI) condensed into a single domain, as characterized for calbindin D28k (Calb), the closest homolog of calretinin. Unperturbed 1H,15N HSQC NMR spectra of a 15N-labeled calretinin fragment (CR III,VI, residues 100,271) in the presence of the unlabeled complimentary fragment (CR I,II, residues 1,100) show that these fragments do not interact. Size exclusion chromatography and affinity chromatography data support this conclusion. The HSQC spectrum of 15N-labeled CR is similar to the overlaid spectra of individual 15N-labeled CR fragments (CR I,II and CR III,VI), also suggesting that these regions do not interact within intact CR. In contrast to these observations, but in accordance with the Calb studies, we observed interactions between other CR fragments: CR I (1,60) with CR II,VI (61,271), and CR I,III (1,142) with CR IV,VI (145,271). We conclude that CR is formed from at least two independent domains consisting of CR I,II and CR III,VI. The differences in domain organization of Calb and CR may explain the specific target interaction of Calb with caspase-3. Most importantly, the comparison of CR and Calb domain organizations questions the value of homologous modeling of EF-hand proteins, and perhaps of other protein families. [source]