Sequences translated by Balbiani ring 75S RNA in vitro are present in giant secretory protein from Chironomus tentans

Chromosoma ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 101-113 ◽  
Author(s):  
L. Rydlander ◽  
A. Pigon ◽  
J. -E. Edstr�m
Parasitology ◽  
2004 ◽  
Vol 129 (3) ◽  
pp. 371-378 ◽  
Author(s):  
D. CARMENA ◽  
J. MARTÍNEZ ◽  
A. BENITO ◽  
J. A. GUISANTES

This study describes, for the first time, the characterization of excretory–secretory antigens (ES-Ag) from Echinococcus granulosus protoscoleces, evaluating their usefulness in the immunodiagnosis of human cystic echinococcosis. ES-Ag were obtained from the first 50 h maintenance of protoscoleces in vitro. This preparation contained over 20 major protein components which could be distinguished by 1-dimensional SDS–PAGE with apparent masses between 9 and 300 kDa. The culture of of protoscoleces from liver produced a greater variety of excretory–secretory protein components than those from lung. Determination of enzymatic activities of secreted proteins revealed the presence of phosphatases, lipases and glucosidases, but no proteases. These findings were compared to those obtained from somatic extracts of protoscoleces and hydatid cyst fluid products. Immunochemical characterization was performed by immunoblotting with sera from individuals infected by cystic echinococcosis (n=15), non-hydatidic parasitoses (n=19), various liver diseases (n=24), lung neoplasia (n=16), and healthy donors (n=18). Antigens with apparent masses of 89, 74, 47/50, 32, and 20 kDa showed specificity for immunodiagnosis of human hydatidosis. The 89 and 74 kDa components corresponded to antigens not yet described in E. granulosus, whereas proteins of 41–43 kDa and 91–95 kDa were recognized by the majority of the non-hydatid sera studied.


Chromosoma ◽  
1981 ◽  
Vol 83 (3) ◽  
pp. 295-313 ◽  
Author(s):  
Adelheid Degelmann ◽  
Cornelis P. Hollenberg

1987 ◽  
Vol 7 (12) ◽  
pp. 4308-4316
Author(s):  
E Egyházi ◽  
E Durban

Purified anti-topoisomerase I immunoglobulin G (IgG) was microinjected into nuclei of Chironomus tentans salivary gland cells, and the effect on DNA transcription was investigated. Synthesis of nucleolar preribosomal 38S RNA by RNA polymerase I and of chromosomal Balbiani ring RNA by RNA polymerase II was inhibited by about 80%. The inhibitory action of anti-topoisomerase I IgG could be reversed by the addition of exogenous topoisomerase I. Anti-topoisomerase I IgG had less effect on RNA polymerase II-promoted activity of other less efficiently transcribing heterogeneous nuclear RNA genes. The pattern of inhibition of growing nascent Balbiani ring chains indicated that the transcriptional process was interrupted at the level of chain elongation. The highly decondensed state of active Balbiani ring chromatin, however, remained unaffected after injection of topoisomerase I antibodies. These data are consistent with the interpretation that topoisomerase I is an essential component in the transcriptional process but not in the maintenance of the decondensed state of active chromatin.


1995 ◽  
Vol 129 (5) ◽  
pp. 1205-1216 ◽  
Author(s):  
H Mehlin ◽  
B Daneholt ◽  
U Skoglund

The transport of Balbiani ring (BR) premessenger RNP particles in the larval salivary gland cells of the dipteran Chironomus tentans can be followed using electron microscopy. A BR RNP particle consists of an RNP ribbon bent into a ringlike structure. Upon translocation through the nuclear pore complex (NPC), the ribbon is straightened and enters the central channel of the NPC with the 5' end of the transcript in the lead. The translocating ribbon is likely to interact with the central channel but, in addition, the remaining portion of the ribbon ring makes contact with the periphery of the NPC. To determine the nature of this latter interaction, we have now studied the connections between the RNP particle and the border of the NPC during different stages of translocation using electron microscope tomography. It was observed that the 3' terminal domain of the ribbon always touches the nuclear ring of the NPC, but the precise area of contact is variable. Sometimes also a region on the opposite side of the ribbon ring reaches the nuclear ring. The pattern of contacts could be correlated to the stage of translocation, and it was concluded that the particle-nuclear ring interactions reflect a rotation of the ribbon ring in front of the central channel, the rotation being secondary to the successive translocation of the ribbon through the channel. The particle's mode of interaction with the NPC suggests that the initial contact between the 5' end domain of the ribbon and the entrance to the central channel is probably crucial to accomplish the ordered translocation of the premessenger RNP particle through the NPC.


2019 ◽  
Vol 3 (2) ◽  

Sperm immobilization factor (SIF), the secretory protein of Staphylococcus aureus, is known to cause complete immobilization, death and morphological alterations in mouse spermatozoa in vitro. However, the present study aims to explore a newer dimension of SIF i.e., to bind to motile and non-motile bacteria and its ability to induce immobilization of motile bacteria in vitro. The results showed that 800µg of SIF caused complete immobilization of motile bacteria, however, death and morphological alterations could not be observed even with 1000µg of SIF. Furthermore, this SIF-mediated bacterial immobilization was reversed when each of the SIF-binding receptor from mouse spermatozoa and bacteria (Escherichia coli and Streptococcus pyogenes) was incubated with bacteria, thereby, providing an experimental evidence of similarity between the antigenic determinants present on spermatozoa and bacteria against a common ligand, SIF.


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