scholarly journals Molecular cloning of integrin-associated protein: an immunoglobulin family member with multiple membrane-spanning domains implicated in alpha v beta 3-dependent ligand binding.

1993 ◽  
Vol 123 (2) ◽  
pp. 485-496 ◽  
Author(s):  
F P Lindberg ◽  
H D Gresham ◽  
E Schwarz ◽  
E J Brown
Keyword(s):  
Ligand Binding ◽  
Cho Cells ◽  
Peptide Sequence ◽  
Human Antibody ◽  
Amino Terminal ◽  
Membrane Spanning ◽  
Highly Hydrophobic ◽  
Leukocyte Response ◽  
Carboxy Terminal ◽  
Alpha V Beta 3

Integrin Associated Protein (IAP) is a 50-kD membrane protein which copurifies with the integrin alpha v beta 3 from placenta and coimmunoprecipitates with beta 3 from platelets. IAP also is functionally associated with signal transduction from the Leukocyte Response Integrin. Using tryptic peptide sequence, human and murine IAP cDNAs have been isolated. The protein has an extracellular amino-terminal immunoglobulin domain that binds all monoclonal anti-IAP antibodies. The carboxy-terminal region is highly hydrophobic with three or five membrane-spanning segments and a short hydrophilic tail. Immunofluorescence microscopy suggests that this hydrophilic tail is located on the inside of the cytoplasmic membrane. Monoclonal anti-IAP antibody inhibits the binding of vitronectin-coated beads to alpha v beta 3 on human erythroleukemia cells, and polyclonal anti-IAP recognizes hamster IAP on CHO cells and inhibits vitronectin bead binding. When CHO cells are transfected with human IAP, monoclonal anti-human antibody completely inhibits vitronectin bead binding. These data suggest a model in which ligand binding by alpha v beta 3 is regulated by IAP.

scholarly journals Multiple genes coding for precursors of rhodotorucine A, a farnesyl peptide mating pheromone of the basidiomycetous yeast Rhodosporidium toruloides.

1989 ◽  
Vol 9 (8) ◽  
pp. 3491-3498 ◽  
Author(s):  
R Akada ◽  
K Minomi ◽  
J Kai ◽  
I Yamashita ◽  
T Miyakawa ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Rhodosporidium Toruloides ◽  
Basidiomycetous Yeast ◽  
Peptide Sequence ◽  
In Vitro Translation ◽  
Mating Pheromone ◽  
S1 Nuclease ◽  
Amino Terminal ◽  
Carboxy Terminal

Haploid cells of mating type A of the basidiomycetous yeast Rhodosporidium toruloides secrete a mating pheromone, rhodotorucine A, which is an undecapeptide containing S-farnesyl cysteine at its carboxy terminus. To analyze the processing and secretion pathway of rhodotorucine A, we isolated both genomic and complementary DNAs encoding the peptide moiety. We identified three distinct genes, RHA1, RHA2, and RHA3, encoding four, five, and three copies of the pheromone peptide, respectively. Complementary DNA clones were classified into two types. One type was homologous to RHA1, and the other type was homologous to RHA2. Transcription start sites were identified by primer extension and S1 nuclease protection, from which the site of the initiator methionine was verified. A primary precursor of rhodotorucine A was detected as a 7-kilodalton protein by immunoprecipitation of in vitro translation products. On the basis of these results, we propose similar three-precursor structures of rhodotorucine A, each containing the amino-terminal peptide sequence Met-Val-Ala. The precursors contain three, four, or five tandem repeats of the pheromone peptide, each separated by a spacer peptide, Thr-Val-Ser(Ala)-Lys, and each precursor has the carboxy-terminal sequence Thr-Val-Ala. This structure suggests that primary precursors of rhodotorucine A do not contain canonical signal sequences.

scholarly journals Protein Translocation across Planar Bilayers by the Colicin Ia Channel-Forming Domain

2000 ◽  
Vol 116 (4) ◽  
pp. 587-598 ◽  
Author(s):  
Paul K. Kienker ◽  
Karen S. Jakes ◽  
Alan Finkelstein
Keyword(s):  
Protein Translocation ◽  
Bilayer Membrane ◽  
Water Soluble ◽  
Planar Bilayers ◽  
Amino Terminal ◽  
Water Soluble Protein ◽  
Voltage Gated Channels ◽  
Membrane Spanning ◽  
Carboxy Terminal ◽  
Colicin Ia

Colicin Ia, a 626-residue bactericidal protein, consists of three domains, with the carboxy-terminal domain (C domain) responsible for channel formation. Whole colicin Ia or C domain added to a planar lipid bilayer membrane forms voltage-gated channels. We have shown previously that the channel formed by whole colicin Ia has four membrane-spanning segments and an ∼68-residue segment translocated across the membrane. Various experimental interventions could cause a longer or shorter segment within the C domain to be translocated, making us wonder why translocation normally stops where it does, near the amino-terminal end of the C domain (approximately residue 450). We hypothesized that regions upstream from the C domain prevent its amino-terminal end from moving into and across the membrane. To test this idea, we prepared C domain with a ligand attached near its amino terminus, added it to one side of a planar bilayer to form channels, and then probed from the opposite side with a water-soluble protein that can specifically bind the ligand. The binding of the probe had a dramatic effect on channel gating, demonstrating that the ligand (and hence the amino-terminal end of the C domain) had moved across the membrane. Experiments with larger colicin Ia fragments showed that a region of more than 165 residues, upstream from the C domain, can also move across the membrane. All of the colicin Ia carboxy-terminal fragments that we examined form channels that pass from a state of relatively normal conductance to a low-conductance state; we interpret this passage as a transition from a channel with four membrane-spanning segments to one with only three.

Multiple genes coding for precursors of rhodotorucine A, a farnesyl peptide mating pheromone of the basidiomycetous yeast Rhodosporidium toruloides

1989 ◽  
Vol 9 (8) ◽  
pp. 3491-3498
Author(s):  
R Akada ◽  
K Minomi ◽  
J Kai ◽  
I Yamashita ◽  
T Miyakawa ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Rhodosporidium Toruloides ◽  
Basidiomycetous Yeast ◽  
Peptide Sequence ◽  
In Vitro Translation ◽  
Mating Pheromone ◽  
S1 Nuclease ◽  
Amino Terminal ◽  
Carboxy Terminal

Haploid cells of mating type A of the basidiomycetous yeast Rhodosporidium toruloides secrete a mating pheromone, rhodotorucine A, which is an undecapeptide containing S-farnesyl cysteine at its carboxy terminus. To analyze the processing and secretion pathway of rhodotorucine A, we isolated both genomic and complementary DNAs encoding the peptide moiety. We identified three distinct genes, RHA1, RHA2, and RHA3, encoding four, five, and three copies of the pheromone peptide, respectively. Complementary DNA clones were classified into two types. One type was homologous to RHA1, and the other type was homologous to RHA2. Transcription start sites were identified by primer extension and S1 nuclease protection, from which the site of the initiator methionine was verified. A primary precursor of rhodotorucine A was detected as a 7-kilodalton protein by immunoprecipitation of in vitro translation products. On the basis of these results, we propose similar three-precursor structures of rhodotorucine A, each containing the amino-terminal peptide sequence Met-Val-Ala. The precursors contain three, four, or five tandem repeats of the pheromone peptide, each separated by a spacer peptide, Thr-Val-Ser(Ala)-Lys, and each precursor has the carboxy-terminal sequence Thr-Val-Ala. This structure suggests that primary precursors of rhodotorucine A do not contain canonical signal sequences.

scholarly journals A specific transmembrane domain of a coronavirus E1 glycoprotein is required for its retention in the Golgi region.

1987 ◽  
Vol 105 (3) ◽  
pp. 1205-1214 ◽  
Author(s):  
C E Machamer ◽  
J K Rose
Keyword(s):  
Transmembrane Domain ◽  
Signal Sequence ◽  
Mutant Protein ◽  
Specific Domain ◽  
Amino Terminal ◽  
Golgi Region ◽  
Membrane Spanning ◽  
Carboxy Terminal ◽  
Amino Terminal Domain ◽  
Membrane Spanning Domains

The E1 glycoprotein of the avian coronavirus infectious bronchitis virus contains a short, glycosylated amino-terminal domain, three membrane-spanning domains, and a long carboxy-terminal cytoplasmic domain. We show that E1 expressed from cDNA is targeted to the Golgi region, as it is in infected cells. E1 proteins with precise deletions of the first and second or the second and third membrane-spanning domains were glycosylated, thus suggesting that either the first or third transmembrane domain can function as an internal signal sequence. The mutant protein with only the first transmembrane domain accumulated intracellularly like the wild-type protein, but the mutant protein with only the third transmembrane domain was transported to the cell surface. This result suggests that information specifying accumulation in the Golgi region resides in the first transmembrane domain, and provides the first example of an intracellular membrane protein that is transported to the plasma membrane after deletion of a specific domain.

scholarly journals Arabidopsis Transmembrane Receptor-Like Kinases (RLKs): A Bridge between Extracellular Signal and Intracellular Regulatory Machinery

2020 ◽  
Vol 21 (11) ◽  
pp. 4000 ◽  
Author(s):  
Jismon Jose ◽  
Swathi Ghantasala ◽  
Swarup Roy Choudhury
Keyword(s):  
Ligand Binding ◽  
Stress Responses ◽  
Tyrosine Kinases ◽  
Functional Characterization ◽  
Kinase Domain ◽  
Amino Terminal ◽  
Binding Domains ◽  
Regulatory Machinery ◽  
Considerable Homology ◽  
Membrane Spanning

Receptors form the crux for any biochemical signaling. Receptor-like kinases (RLKs) are conserved protein kinases in eukaryotes that establish signaling circuits to transduce information from outer plant cell membrane to the nucleus of plant cells, eventually activating processes directing growth, development, stress responses, and disease resistance. Plant RLKs share considerable homology with the receptor tyrosine kinases (RTKs) of the animal system, differing at the site of phosphorylation. Typically, RLKs have a membrane-localization signal in the amino-terminal, followed by an extracellular ligand-binding domain, a solitary membrane-spanning domain, and a cytoplasmic kinase domain. The functional characterization of ligand-binding domains of the various RLKs has demonstrated their essential role in the perception of extracellular stimuli, while its cytosolic kinase domain is usually confined to the phosphorylation of their substrates to control downstream regulatory machinery. Identification of the several ligands of RLKs, as well as a few of its immediate substrates have predominantly contributed to a better understanding of the fundamental signaling mechanisms. In the model plant Arabidopsis, several studies have indicated that multiple RLKs are involved in modulating various types of physiological roles via diverse signaling routes. Here, we summarize recent advances and provide an updated overview of transmembrane RLKs in Arabidopsis.

scholarly journals Thyroid Hormone Receptors in Two Model Species for Vertebrate Embryonic Development: Chicken and Zebrafish

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Veerle M. Darras ◽  
Stijn L. J. Van Herck ◽  
Marjolein Heijlen ◽  
Bert De Groef
Keyword(s):  
Thyroid Hormone ◽  
Embryonic Development ◽  
Ligand Binding ◽  
Hormone Receptors ◽  
Thyroid Hormone Receptor ◽  
Hormone Treatment ◽  
Model Species ◽  
Amino Terminal ◽  
Carboxy Terminal ◽  
Amino Terminal Domain

Chicken and zebrafish are two model species regularly used to study the role of thyroid hormones in vertebrate development. Similar to mammals, chickens have one thyroid hormone receptorα(TRα) and one TRβgene, giving rise to three TR isoforms: TRα, TRβ2, and TRβ0, the latter with a very short amino-terminal domain. Zebrafish also have one TRβgene, providing two TRβ1 variants. The zebrafish TRαgene has been duplicated, and at least three TRαisoforms are expressed: TRαA1-2 and TRαB are very similar, while TRαA1 has a longer carboxy-terminal ligand-binding domain. All these TR isoforms appear to be functional, ligand-binding receptors. As in other vertebrates, the different chicken and zebrafish TR isoforms have a divergent spatiotemporal expression pattern, suggesting that they also have distinct functions. Several isoforms are expressed from the very first stages of embryonic development and early chicken and zebrafish embryos respond to thyroid hormone treatment with changes in gene expression. Future studies in knockdown and mutant animals should allow us to link the different TR isoforms to specific processes in embryonic development.

scholarly journals Sizing the Protein Translocation Pathway of Colicin Ia Channels

2003 ◽  
Vol 122 (2) ◽  
pp. 161-176 ◽  
Author(s):  
Paul K. Kienker ◽  
Karen S. Jakes ◽  
Robert O. Blaustein ◽  
Christopher Miller ◽  
Alan Finkelstein
Keyword(s):  
Lipid Bilayers ◽  
Single Channel ◽  
Bacterial Toxin ◽  
Upstream Region ◽  
Amino Terminus ◽  
Amino Terminal ◽  
Translocation Pathway ◽  
Membrane Spanning ◽  
Carboxy Terminal ◽  
Colicin Ia

The bacterial toxin colicin Ia forms voltage-gated channels in planar lipid bilayers. The toxin consists of three domains, with the carboxy-terminal domain (C-domain) responsible for channel formation. The C-domain contributes four membrane-spanning segments and a 68-residue translocated segment to the open channel, whereas the upstream domains and the amino-terminal end of the C-domain stay on the cis side of the membrane. The isolated C-domain, lacking the two upstream domains, also forms channels; however, the amino terminus and one of the normally membrane-spanning segments can move across the membrane. (This can be observed as a drop in single-channel conductance.) In longer carboxy-terminal fragments of colicin Ia that include ≤169 residues upstream from the C-domain, the entire upstream region is translocated. Presumably, a portion of the C-domain creates a pathway for the polar upstream region to move through the membrane. To determine the size of this translocation pathway, we have attached “molecular stoppers,” small disulfide-bonded polypeptides, to the amino terminus of the C-domain, and determined whether they could be translocated. We have found that the translocation rate is strongly voltage dependent, and that at voltages ≥90 mV, even a 26-Å stopper is translocated. Upon reduction of their disulfide bonds, all of the stoppers are easily translocated, indicating that it is the folded structure, rather than some aspect of the primary sequence, that slows translocation of the stoppers. Thus, the pathway for translocation is ≥26 Å in diameter, or can stretch to this value. This is large enough for an α-helical hairpin to fit through.

Interaction Between Mutations in the suppressor of Hairy wing and modifier of mdg4 Genes of Drosophila melunogaster Affecting the Phenotype of gypsy-Induced Mutations

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 425-436 ◽  
Author(s):  
Pavel Georgiev ◽  
Marina Kozycina
Keyword(s):  
Mutagenic Effect ◽  
Induced Mutations ◽  
Binding Region ◽  
Direct Inhibition ◽  
Amino Terminal ◽  
Acidic Domain ◽  
Complete Inactivation ◽  
Insulation Effect ◽  
Gypsy Retrotransposon ◽  
Carboxy Terminal

Abstract The suppressor of Hairy-wing [su(Hw)] protein mediates the mutagenic effect of the gypsy retrotransposon by repressing the function of transcriptional enhancers located distally from the promoter with respect to the position of the su(Hw)-binding region. Mutations in a second gene, modifier of mdg4, also affect the gypsy-induced phenotype. Two major effects of the mod(mdg4)lul mutation can be distinguished: the interference with insulation by the su(Hw)-binding region and direct inhibition of gene expression that is not dependent on the su(Hw)-binding region position. The mod(mdg4)lul mutation partially suppresses ct6, scD1 and Hw1 mutations, possibly by interfering with the insulation effect of the su(Hw)-binding region. An example of the second effect of mod(mdg4)lul is a complete inactivation of yellow expression in combination with the y  2 allele. Phenotypic analyses of flies with combinations of mod(mdg4)lul and different su(Hw) mutations, or with constructions carrying deletions of the acidic domains of the su(Hw) protein, suggest that the carboxy-terminal acidic domain is important for direct inhibition of yellow transcription in bristles, while the amino-terminal acidic domain is more essential for insulation.

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