Search results for "DOMAIN"
showing 10 items of 2485 documents
Cold stress defense in the freshwater sponge Lubomirskia baicalensis
2007
The endemic freshwater sponge Lubomirskia baicalensis lives in Lake Baikal in winter (samples from March have been studied) under complete ice cover at near 0 degrees C, and in summer in open water at 17 degrees C (September). In March, specimens show high metabolic activity as reflected by the production of gametes. L. baicalensis lives in symbiosis with green dinoflagellates, which are related to Gymnodinium sanguineum. Here we show that these dinoflagellates produce the toxin okadaic acid (OA), which is present as a free molecule as well as in a protein-bound state. In metazoans OA inhibits both protein phosphatase-2A and protein phosphatase-1 (PP1). Only cDNA corresponding to PP1 could …
Molecular cloning of a tyrosine kinase gene from the marine spongeGeodia cydonium: a new member belonging to the receptor tyrosine kinase class II fa…
1994
We have isolated and characterized a cDNA from the marine sponge Geodia cydonium coding for a new member of the tyrosine protein kinase (TK) family. The cDNA encodes a protein of M(r) = 68,710, termed GCTK, which is homologous to class II receptor tyrosine kinases (RTKs). GCTK contains conserved amino acids (aa) characteristic of all protein kinases, and the sequences DLATRN and PIRWMATE which are highly specific for TKs. Furthermore, the sequence N-L-Y-x(3)-Y-Y-R is highly homologous to the sequence D-[LIV]-Y-x(3)-Y-Y-R found only in class II RTKs. The sponge TK, when compared with mammalian class II RTKs, shows maximum 31% homology in the TK domain indicating that this the oldest member o…
Tumor necrosis factor-alpha converting enzyme is processed by proprotein-convertases to its mature form which is degraded upon phorbol ester stimulat…
2003
Tumor necrosis factor-alpha converting enzyme (TACE or ADAM17) is a member of the ADAM (a disintegrin and metalloproteinase) family of type I membrane proteins and mediates the ectodomain shedding of various membrane-anchored signaling and adhesion proteins. TACE is synthesized as an inactive zymogen, which is subsequently proteolytically processed to the catalytically active form. We have identified the proprotein-convertases PC7 and furin to be involved in maturation of TACE. This maturation is negatively influenced by the phorbol ester phorbol-12-myristate-13-acetate (PMA), which decreases the cellular amount of the mature form of TACE in PMA-treated HEK293 and SH-SY5Y cells. Furthermore…
Isolation and characterization of five Fox (Forkhead) genes from the sponge Suberites domuncula.
2003
Fox or Forkhead genes constitute a subgroup of the helix-turn-helix class of transcription factors with a characteristic and highly conserved DNA binding domain. To date, around 100 different Fox genes have been reported ranging from yeast to humans; these have been classified into 18 subclasses (A to P). Fox proteins are responsible for a wide range of functions and key roles in early developmental processes, during organogenesis and also for the function of the major organs and tissues in the adult. Here, we report the isolation and phylogenetic characterization of five members of the Fox family from the sponge Suberites domuncula. Four of them (Sd-FoxL2, Sd-FoxP, Sd-FoxD and Sd-FoxF) fal…
Characterization of a cDNA encoding RP43, a CUB-domain-containing protein from the tube of Riftia pachyptila (Vestimentifera), and distribution of it…
2000
A major 43kDa protein from the protective tube of Riftiapachyptila (Vestimentifera), named RP43, was partly microsequenced after isolation by SDS/PAGE from the protein fraction of tubes collected around the hydrothermal vents at the East Pacific Rise. On the basis of the partial peptide sequences obtained, experiments using reverse-transcriptase-mediated PCR and rapid amplification of cDNA ends led to the complete cDNA sequence. Analysis of deduced amino acid sequence of RP43 showed the presence of CUB domains (100–110-residue-spanning domains first reported in the complement subcomponents C1r/C1s, epidermal-growth-factor-related sea urchin protein and bone morphogenetic protein 1) that se…
Cloning and expression of new receptors belonging to the immunoglobulin superfamily from the marine sponge Geodia cydonium
1999
A cDNA encoding a receptor tyrosine kinase (RTK) was previously cloned and expressed from the marine sponge (Porifera) Geodia cydonium. In addition to the two intracellular regions characteristic for RTKs, two immunoglobulin (Ig)-like domains are found in the extracellular part of the sponge RTK. In the present study it is shown that no further Ig-like domain is present in the upstream region of the cDNA as well as of the gene hitherto known from the sponge RTK. Two different full-length cDNAs have been isolated and characterized in the present study, which possess two Ig-like domains, one transmembrane segment, and only a short intracellular part, without a TK domain. The two deduced polyp…
Characterization and phylogenetic analysis of a cDNA encoding the Fes/FER related, non-receptor protein-tyrosine kinase in the marine sponge Sycon ra…
1998
Abstract In search of ancient versions of phylogenetically conserved genes/proteins, which are typical for multicellular animals, we have decided to analyse marine sponges (Porifera), the most ancient and most primitive metazoan organisms. We report here the complete nucleotide sequence of Sycon raphanus cDNA coding for a 879 aa long protein (100 kDa), which displays high overall similarity in primary structure and organization of domains with non-receptor tyrosine kinases (TKs) from the Fes/FER family. The encoded protein, which we named Fes/FER_SR, has a highly conserved, 260 aa long tyrosine kinase domain at the C-terminus. Amino-terminal to the catalytic domain is an 85 aa long SH2 doma…
Src proteins/src genes: from sponges to mammals
2004
The genome of marine sponge Suberites domuncula, a member of the most ancient and most simple metazoan phylum Porifera, encodes at least five genes for Src-type proteins, more than, i.e., Caenorhabditis elegans or Drosophila melanogaster (two in each). Three proteins, SRC1SD, SRC2SD and SRC3SD, were fully characterized. The overall homology (identity+similarity) among the three S. domuncula Srcs (68-71%) is much lower than the sequence conservation between orthologous Src proteins from freshwater sponges (82-85%). It is therefore very likely that several src genes/proteins were already present in the genome of Urmetazoa, the hypothetical metazoan ancestor. We have identified in the S. domun…
Immunoglobulin-like domain is present in the extracellular part of the receptor tyrosine kinase from the marine sponge Geodia cydonium.
1994
We have isolated and characterized two cDNAs from the marine sponge Geodia cydonium coding for a new member of a receptor tyrosine kinase of class II. The deduced amino acid sequence shows two characteristic domains: (i) the tyrosine kinase domain; and (ii) and immunoglobulin-like domain. The latter part shows high homology to the vertebrate C2 type immunoglobulin domain. This result demonstrates that immunoglobulin domains are not recent achievements of higher animals but exist also in those animals which have diverged from other organisms about 800 million years ago.
DNS Tunneling Detection Techniques – Classification, and Theoretical Comparison in Case of a Real APT Campaign
2017
Domain Name System (DNS) plays an important role as a translation protocol in everyday use of the Internet. The purpose of DNS is to translate domain names into IP addresses and vice versa. However, its simple architecture can easily be misused for malicious activities. One huge security threat concerning DNS is tunneling, which helps attackers bypass the security systems unnoticed. A DNS tunnel can be used for three purposes: as a command and control channel, for data exfiltration or even for tunneling another protocol through it. In this paper, we surveyed different techniques for DNS tunneling detection. We classified those first based on the type of data and then within the categories b…