scholarly journals The Drosophila Polycomb-group gene Enhancer of zeste contains a region with sequence similarity to trithorax.

1993 ◽  
Vol 13 (10) ◽  
pp. 6357-6366 ◽  
Author(s):  
R S Jones ◽  
W M Gelbart
Keyword(s):  
Amino Acids ◽  
Sequence Similarity ◽  
Protein Product ◽  
Polycomb Group ◽  
Acute Leukemias ◽  
Trithorax Group ◽  
Acid Protein ◽  
Enhancer Of Zeste ◽  
Gene Enhancer ◽  
Carboxy Terminal

As is typical of Polycomb-group loci, the Enhancer of zeste [E(z)] gene negatively regulates the segment identity genes of the Antennapedia (ANT-C) and Bithorax (BX-C) gene complexes. A second class of loci, collectively known as the trithorax group, plays an antagonistic role as positive regulators of the ANT-C and BX-C genes. Molecular analysis of the E(z) gene predicts a 760-amino-acid protein product. A region of 116 amino acids near the E(z) carboxy terminus is 41.2% identical (68.4% similar) with a carboxy-terminal region of the trithorax protein. This portion of the trithorax protein is part of a larger region previously shown to share extensive homology with a human protein (ALL-1/Hrx) that is implicated in acute leukemias. Over this same 116 amino acids, E(z) and ALL-1/Hrx are 43.9% identical (68.4% similar). Otherwise, E(z) is not significantly similar to any previously described proteins. As this region of sequence similarity is shared by two proteins with antagonistic functions, we suggest that it may comprise a domain that interacts with a common target, either nucleic acid or protein. Opposite effects on transcription might then be determined by other portions of the two proteins.

The Drosophila Polycomb-group gene Enhancer of zeste contains a region with sequence similarity to trithorax

1993 ◽  
Vol 13 (10) ◽  
pp. 6357-6366
Author(s):  
R S Jones ◽  
W M Gelbart
Keyword(s):  
Amino Acids ◽  
Sequence Similarity ◽  
Protein Product ◽  
Polycomb Group ◽  
Acute Leukemias ◽  
Trithorax Group ◽  
Acid Protein ◽  
Enhancer Of Zeste ◽  
Gene Enhancer ◽  
Carboxy Terminal

As is typical of Polycomb-group loci, the Enhancer of zeste [E(z)] gene negatively regulates the segment identity genes of the Antennapedia (ANT-C) and Bithorax (BX-C) gene complexes. A second class of loci, collectively known as the trithorax group, plays an antagonistic role as positive regulators of the ANT-C and BX-C genes. Molecular analysis of the E(z) gene predicts a 760-amino-acid protein product. A region of 116 amino acids near the E(z) carboxy terminus is 41.2% identical (68.4% similar) with a carboxy-terminal region of the trithorax protein. This portion of the trithorax protein is part of a larger region previously shown to share extensive homology with a human protein (ALL-1/Hrx) that is implicated in acute leukemias. Over this same 116 amino acids, E(z) and ALL-1/Hrx are 43.9% identical (68.4% similar). Otherwise, E(z) is not significantly similar to any previously described proteins. As this region of sequence similarity is shared by two proteins with antagonistic functions, we suggest that it may comprise a domain that interacts with a common target, either nucleic acid or protein. Opposite effects on transcription might then be determined by other portions of the two proteins.

scholarly journals Trans-Silencing by P Elements Inserted in Subtelomeric Heterochromatin Involves the Drosophila Polycomb Group Gene, Enhancer of zeste

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1839-1855 ◽  
Author(s):  
Siobhan E Roche ◽  
Donald C Rio
Keyword(s):  
Transcriptional Repression ◽  
Protein Product ◽  
Polycomb Group ◽  
P Element ◽  
Subtelomeric Heterochromatin ◽  
P Elements ◽  
Enhancer Of Zeste ◽  
Gene Enhancer ◽  
Associated Sequences ◽  
Polycomb Group Gene

AbstractDrosophila P-element transposition is regulated by a maternally inherited state known as P cytotype. An important aspect of P cytotype is transcriptional repression of the P-element promoter. P cytotype can also repress non-P-element promoters within P-element ends, suggesting that P cytotype repression might involve chromatin-based transcriptional silencing. To learn more about the role of chromatin in P cytotype repression, we have been studying the P strain Lk-P(1A). This strain contains two full-length P elements inserted in the heterochromatic telomere-associated sequences (TAS elements) at cytological location 1A. Mutations in the Polycomb group gene (Pc-G gene), Enhancer of zeste (E(z)), whose protein product binds at 1A, resulted in a loss of Lk-P(1A) cytotype control. E(z) mutations also affected the trans-silencing of heterologous promoters between P-element termini by P-element transgenes inserted in the TAS repeats. These data suggest that pairing interactions between P elements, resulting in exchange of chromatin structures, may be a mechanism for controlling the expression and activity of P elements.

scholarly journals The Drosophila ash1 Gene Product, Which Is Localized at Specific Sites on Polytene Chromosomes, Contains a SET Domain and a PHD Finger

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 913-928 ◽  
Author(s):  
Nicholas Tripoulas ◽  
Dennis LaJeunesse ◽  
John Gildea ◽  
Allen Shearn
Keyword(s):  
Amino Acids ◽  
Polytene Chromosomes ◽  
Protein Product ◽  
Polycomb Group ◽  
Transcriptional Level ◽  
Set Domain ◽  
Trithorax Group ◽  
Phd Finger ◽  
Polycomb Group Genes ◽  
The Stability

Abstract The determined state of Drosophila imaginal discs depends on stable patterns of homeotic gene expression. The stability of these patterns requires the function of the ash1 gene, a member of the trithorax group. The primary translation product of the 7.5-kb ash1 transcript is predicted to be a basic protein of 2144 amino acids. The ASHl protein contains a SET domain and a PHD finger. Both of these motifs are found in the products of some trithorax group and Polycomb group genes. We have determined the nucleotide sequence alterations in 10 ash1 mutant alleles and have examined their mutant phenotype. The best candidate for a null allele is ashl  22. The truncated protein product of this mutant allele is predicted to contain only 47 amino acids. The ASHl protein is localized on polytene chromosomes of larval salivary glands at >100 sites. The chromosomal localization of ASHl implies that it functions at the transcriptional level to maintain the expression pattern of homeotic selector genes.

E(z): a polycomb group gene or a trithorax group gene?

Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2189-2197 ◽  
Author(s):  
D. LaJeunesse ◽  
A. Shearn
Keyword(s):  
Polycomb Group ◽  
Bithorax Complex ◽  
Trithorax Group ◽  
Polycomb Group Genes ◽  
Enhancer Of Zeste ◽  
Selector Genes ◽  
Homeotic Selector Genes ◽  
Polycomb Group Gene ◽  
Anterior Posterior ◽  
Homeotic Selector

The products of the Polycomb group of genes are cooperatively involved in repressing expression of homeotic selector genes outside of their appropriate anterior/posterior boundaries. Loss of maternal and/or zygotic function of Polycomb group genes results in the ectopic expression of both Antennapedia Complex and Bithorax Complex genes. The products of the trithorax group of genes are cooperatively involved in maintaining active expression of homeotic selector genes within their appropriate anterior/posterior boundaries. Loss of maternal and/or zygotic function of trithorax group genes results in reduced expression of both Antennapedia Complex and Bithorax Complex genes. Although Enhancer of zeste has been classified as a member of the Polycomb group, in this paper we show that Enhancer of zeste can also be classified as a member of the trithorax group. The requirement for Enhancer of zeste activity as either a trithorax group or Polycomb group gene depends on the homeotic selector gene locus as well as on spatial and temporal cues.

scholarly journals Pex19p Interacts with Pex3p and Pex10p and Is Essential for Peroxisome Biogenesis in Pichia pastoris

1999 ◽  
Vol 10 (6) ◽  
pp. 1745-1761 ◽  
Author(s):  
William B. Snyder ◽  
Klaas Nico Faber ◽  
Thibaut J. Wenzel ◽  
Antonius Koller ◽  
Georg H. Lüers ◽  
...  
Keyword(s):  
Amino Acids ◽  
Pichia Pastoris ◽  
Early Stage ◽  
Sequence Similarity ◽  
Chinese Hamster ◽  
Peroxisome Biogenesis ◽  
Amino Terminal ◽  
Acid Protein ◽  
Peroxisomal Targeting ◽  
Two Hybrid

We report the cloning and characterization of Pichia pastoris PEX19 by complementation of a peroxisome-deficient mutant strain. Import of peroxisomal targeting signal 1- and 2-containing peroxisomal matrix proteins is defective inpex19 mutants. PEX19 encodes a hydrophilic 299-amino acid protein with sequence similarity toSaccharomyces cerevisiae Pex19p and human and Chinese hamster PxF, all farnesylated proteins, as well as hypothetical proteins from Caenorhabditis elegans andSchizosaccharomyces pombe. The farnesylation consensus is conserved in PpPex19p but dispensable for function and appears unmodified under the conditions tested. Pex19p localizes predominantly to the cytosolic fraction. Biochemical and two-hybrid analyses confirmed that Pex19p interacts with Pex3p, as seen in S. cerevisiae, but unexpectedly also with Pex10p. Two-hybrid analysis demonstrated that the amino-terminal 42 amino acids of Pex19p interact with the carboxyl-terminal 335 amino acids of Pex3p. In addition, the extreme carboxyl terminus of Pex19p (67 amino acids) is required for interaction with the amino-terminal 380 amino acids of Pex10p. Biochemical and immunofluorescence microscopy analyses ofpex19Δ cells identified the membrane protein Pex3p in peroxisome remnants that were not previously observed in S. cerevisiae. These small vesicular and tubular (early) remnants are morphologically distinct from other Pppex mutant (late) remnants, suggesting that Pex19p functions at an early stage of peroxisome biogenesis.

scholarly journals Mutagenesis and chimeric genes define determinants in the beta subunits of human chorionic gonadotropin and lutropin for secretion and assembly.

1989 ◽  
Vol 109 (4) ◽  
pp. 1429-1438 ◽  
Author(s):  
M M Matzuk ◽  
M M Spangler ◽  
M Camel ◽  
N Suganuma ◽  
I Boime
Keyword(s):  
Amino Acids ◽  
Chorionic Gonadotropin ◽  
Sequence Similarity ◽  
Beta Subunits ◽  
Glycoprotein Hormone ◽  
Amino Acid Homology ◽  
Chimeric Genes ◽  
Terminal Amino ◽  
Carboxy Terminal ◽  
High Degree

Chorionic gonadotropin (CG) and lutropin (LH) are members of a family of glycoprotein hormones that share a common alpha subunit but differ in their hormone-specific beta subunits. The glycoprotein hormone beta subunits share a high degree of amino acid homology that is most evident for the LH beta and CG beta subunits having greater than 80% sequence similarity. However, transfection studies have shown that human CG beta and alpha can be secreted as monomers and can combine efficiently to form dimer, whereas secretion and assembly of human LH beta is less efficient. To determine which specific regions of the LH beta and CG beta subunits are responsible for these differences, mutant and chimeric LH beta-CG beta genes were constructed and transfected into CHO cells. Expression of these subunits showed that both the hydrophobic carboxy-terminal seven amino acids and amino acids Trp8, Ile15, Met42, and Asp77 together inhibit the secretion of LH beta. The carboxy-terminal amino acids, along with Trp8, Ile15, Met42, and Thr58 are implicated in the delayed assembly of LH beta. These unique features of LH beta may also play an important role in pituitary intracellular events and may be responsible for the differential glycosylation and sorting of LH and FSH in gonadotrophs.

scholarly journals Assembly of flagellar radial spoke proteins in Chlamydomonas: identification of the axoneme binding domain of radial spoke protein 3.

1993 ◽  
Vol 123 (1) ◽  
pp. 183-190 ◽  
Author(s):  
D R Diener ◽  
L H Ang ◽  
J L Rosenbaum
Keyword(s):  
Amino Acids ◽  
Binding Activity ◽  
Binding Domain ◽  
Flagellar Motility ◽  
Radial Spoke ◽  
Acid Protein ◽  
Radial Spokes ◽  
Carboxy Terminal ◽  
Amino Acid Protein

Radial spokes of the eukaryotic flagellum extend from the A tubule of each outer doublet microtubule toward the central pair microtubules. In the paralyzed flagella mutant of Chlamydomonas pf14, a mutation in the gene for one of 17 polypeptides that comprise the radial spokes results in flagella that lack all 17 spoke components. The defective gene product, radial spoke protein 3 (RSP3), is, therefore, pivotal to the assembly of the entire spoke and may attach the spoke to the axoneme. We have synthesized RSP3 in vitro and assayed its binding to axonemes from pf14 cells to determine if RSP3 can attach to spokeless axonemes. In vitro, RSP3 binds to pf14 axonemes, but not to wild-type axonemes or microtubules polymerized from purified chick brain tubulin. The sole axoneme binding domain of RSP3 is located within amino acids 1-85 of the 516 amino acid protein; deletion of these amino acids abolishes binding by RSP3. Fusion of amino acids 1-85 or 42-85 to an unrelated protein confers complete or partial binding activity, respectively, to the fusion protein. Transformation of pf14 cells with mutagenized RSP3 genes indicates that amino acids 18-87 of RSP3 are important to its function, but that the carboxy-terminal 140 amino acids can be deleted with little effect on radial spoke assembly or flagellar motility.

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