Differential expression of Broad-Complex transcription factors may forecast tissue-specific developmental fates during Drosophila metamorphosis

Development ◽  
1994 ◽  
Vol 120 (11) ◽  
pp. 3275-3287 ◽  
Author(s):  
I.F. Emery ◽  
V. Bedian ◽  
G.M. Guild
Keyword(s):  
Western Blot ◽  
Expression Patterns ◽  
Primary Response ◽  
Protein Isoforms ◽  
Secondary Response ◽  
C Protein ◽  
Tissue Specific ◽  
Specific Outcome ◽  
C Proteins ◽  
Broad Complex

The steroid hormone ecdysone initiates metamorphosis in Drosophila melanogaster by activating a cascade of gene activity that includes primary response transcriptional regulators and secondary response structural genes. The Broad-Complex (BR-C) primary response gene is composed of several distinct genetic functions and encodes a family of related transcription factor isoforms. Our objective was to determine whether BR-C isoforms were components of the primary ecdysone response in all tissues and whether tissue-specific isoform expression is associated with tissue-specific metamorphic outcomes. We used specific antibody reagents that recognize and distinguish among the Z1, Z2 and Z3 BR-C protein isoforms to study protein expression patterns during the initial stages of metamorphosis. Western blot analyses demonstrated that BR-C isoforms are induced at the onset of metamorphosis, each with unique kinetics of induction and repression. Whole-mount immunostaining showed that the BR-C proteins accumulate in the nuclei of all larval and imaginal tissues indicating that the BR-C is induced as a primary response in many tissues. Several tissues express different levels and combinations of the BR-C isoforms suggesting that the BR-C is important in determining the tissue-specific outcome of many parallel ecdysone response cascades. For example, prepupal salivary glands (destined for histolysis during metamorphosis) express Z1 isoforms while imaginal discs (destined for cell differentiation and morphogenesis) shift from the synthesis of Z2 isoforms to the synthesis of Z1 isoforms. The prepupal central nervous system (destined for tissue remodeling) expresses all isoforms, with Z3 predominating. Salivary gland chromosome immunostaining indicated that BR-C proteins interact directly with numerous loci in the polytene genome. Finally, western blot analyses showed that distinct BR-C genetic functions can be correlated with single and specific BR-C protein isoforms.

scholarly journals Localization of C-protein isoforms in chicken skeletal muscle: ultrastructural detection using monoclonal antibodies.

1984 ◽  
Vol 98 (4) ◽  
pp. 1514-1522 ◽  
Author(s):  
J E Dennis ◽  
T Shimizu ◽  
F C Reinach ◽  
D A Fischman
Keyword(s):  
Skeletal Muscle ◽  
Monoclonal Antibodies ◽  
Fiber Type ◽  
Ultrastructural Localization ◽  
Absolute Number ◽  
Protein Isoforms ◽  
C Protein ◽  
Thick Filaments ◽  
C Proteins ◽  
Chicken Skeletal Muscle

Monoclonal antibodies (McAbs) specific for the fast (MF-1) and slow (ALD-66) isoforms of C-protein from chicken skeletal muscle have been produced and characterized. Using these antibodies it was possible to demonstrate that skeletal muscles of varying fiber type express different isoforms of this protein and that in the posterior latissimus dorsi muscle both isoforms are co-expressed in the same myofiber (17, 18). Since we had shown that both isoforms were present in all sarcomeres, it was feasible to test whether the two isoforms co-distributed in the same 43-nm repeat within the A-band, thereby establishing a minimum number of C-proteins per repeat in the thick filaments. Here we describe the ultrastructural localization of C-protein in myofibers from three muscle types of the chicken using these same McAbs. We observed that although C-protein was present in a 43-nm repeat along the filaments in all three muscles, there were marked differences in the absolute number and position occupied by the different isoforms. Since McAbs MF-1 and ALD-66 decorated the same 43-nm repeats in the A-bands of the posterior latissimus dorsal muscle, we suggest that at least two C-proteins can co-localize at binding sites 43 nm apart along thick filaments of this muscle.

The Drosophila Broad-Complex plays a key role in controlling ecdysone-regulated gene expression at the onset of metamorphosis

Development ◽  
1993 ◽  
Vol 118 (3) ◽  
pp. 977-988 ◽  
Author(s):  
F.D. Karim ◽  
G.M. Guild ◽  
C.S. Thummel
Keyword(s):  
High Titer ◽  
Polytene Chromosomes ◽  
Solid Substrate ◽  
Primary Response ◽  
Gene Activity ◽  
Secondary Response ◽  
Receptor Protein ◽  
Regulated Gene Expression ◽  
Broad Complex ◽  
Third Instar Larvae

During Drosophila third instar larval development, one or more pulses of the steroid hormone ecdysone activate three temporally distinct sets of genes in the salivary glands, represented by puffs in the polytene chromosomes. The intermolt genes are induced first, in mid-third instar larvae; these genes encode a protein glue used by the animal to adhere itself to a solid substrate for metamorphosis. The intermolt genes are repressed at puparium formation as a high titer ecdysone pulse directly induces a small set of early regulatory genes. The early genes both repress their own expression and activate more than 100 late secondary-response genes. The Broad-Complex (BR-C) is an early ecdysone-inducible gene that encodes a family of DNA binding proteins defined by at least three lethal complementation groups: br, rbp, and l(1)2Bc. We have found that the BR-C is critical for the appropriate regulation of all three classes of ecdysone-inducible genes. Both rbp and l(1)2Bc are required for glue gene induction in mid-third instar larvae. In addition, the l(1)2Bc function is required for glue gene repression in prepupae; in l(1)2Bc mutants the glue genes are re-induced by the late prepupal ecdysone pulse, recapitulating a mid-third instar regulatory response at an inappropriate stage in development. The l(1)2Bc function is also required for the complete ecdysone induction of some early mRNAs (E74A, E75A, and BR-C) and efficient repression of most early mRNAs in prepupae. Like the intermolt secondary-response genes, the late secondary-response genes are absolutely dependent on rbp for their induction. An effect of l(1)2Bc mutations on late gene activity can also be detected, but is most likely a secondary consequence of the submaximal ecdysone-induction of a subset of early regulatory products. Our results indicate that the BR-C plays a key role in dictating the stage-specificity of the ecdysone response. In addition, the ecdysone-receptor protein complex alone is not sufficient for appropriate induction of the early primary-response genes, but requires the prior expression of BR-C proteins. These studies define the BR-C as a key regulator of gene activity at the onset of metamorphosis in Drosophila.

scholarly journals Human ERRγ, a Third Member of the Estrogen Receptor-Related Receptor (ERR) Subfamily of Orphan Nuclear Receptors: Tissue-Specific Isoforms Are Expressed during Development and in the Adult

2000 ◽  
Vol 14 (3) ◽  
pp. 382-392 ◽  
Author(s):  
David J. Heard ◽  
Peder L. Norby ◽  
Jim Holloway ◽  
Henrik Vissing
Keyword(s):  
Estrogen Receptor ◽  
Nuclear Receptors ◽  
Expression Patterns ◽  
Protein Isoforms ◽  
Hek293 Cells ◽  
Receptor Protein ◽  
Orphan Nuclear Receptors ◽  
Independent Manner ◽  
Tissue Specific ◽  
Alternatively Spliced

Abstract The nuclear receptor protein superfamily is a large group of transcription factors involved in many aspects of animal development, tissue differentiation, and homeostasis in the higher eukaryotes. A subfamily of receptors, ERRα and β (estrogen receptor-related receptor α and β), closely related to the ER, were among the first orphan nuclear receptors identified. These receptors can bind DNA as monomers and are thought to activate transcription constitutively, unaffected by β-estradiol. Studies of the expression patterns of ERRα and gene disruption experiments of ERRβ indicate that they play an important role in the development and differentiation of specific tissues in the mouse. In this work we demonstrate the existence in humans of a third member of this subfamily of receptors, termed ERRγ, which is highly expressed in a number of diverse fetal and adult tissues including brain, kidney, pancreas, and placenta. The ERRγ mRNA is highly alternatively spliced at the 5′-end, giving rise to a number of tissue-specific RNA species, some of which code for protein isoforms differing in the N-terminal region. Like ERRα andβ , ERRγ binds as a monomer to an ERRE. A GAL4-ERRγ fusion protein activates transcription in a ligand-independent manner in transfected HEK293 cells to a greater degree than either the GAL4-ERRα or -β fusion proteins.

scholarly journals The ecdysone-inducible Broad-complex and E74 early genes interact to regulate target gene transcription and Drosophila metamorphosis.

Genetics ◽  
1995 ◽  
Vol 141 (3) ◽  
pp. 1025-1035 ◽  
Author(s):  
J C Fletcher ◽  
C S Thummel
Keyword(s):  
Transcription Factors ◽  
Gene Transcription ◽  
Synergistic Effects ◽  
Group Analysis ◽  
Complementation Group ◽  
Primary Response ◽  
Early Gene ◽  
Secondary Response ◽  
Insect Metamorphosis ◽  
Broad Complex

Abstract Pulses of the steroid hormone ecdysone initiate Drosophila metamorphosis by inducing widespread changes in gene expression. The Broad-Complex (BR-C) and E74 are induced directly by ecdysone and encode families of transcription factors that regulate ecdysone primary- and secondary-response genes. Genetic analyses have revealed that mutations in the BR-C and E74 are lethal during metamorphosis and that these mutations cause some similar lethal phenotypes and alterations in secondary-response gene transcription. To examine whether the BR-C and E74 function together during development, we have combined representative alleles from each BR-C and E74 complementation group. Analysis of the morphological and molecular phenotypes of the double-mutant animals reveals that BR-C and E74 alleles act together to produce both novel and synergistic effects. We find that the BR-C and E74 share functions in puparium formation, pupation and early gene induction. In addition, our evidence suggests that the BR-C and E74 transcription factors may directly interact to regulate the expression of salivary gland glue and late genes. This data is consistent with current models which propose that combinations of ecdysone primary-response genes regulate common morphogenetic pathways during insect metamorphosis.

Distribution of c-protein isoforms in sarcomeres of developing chick skeletal muscle

1988 ◽  
Vol 46 ◽  
pp. 226-227
Author(s):  
D. A. Fischman ◽  
J. E. Dennis ◽  
T. Obinata ◽  
H. Takano-Ohmuro
Keyword(s):  
Skeletal Muscles ◽  
Thick Filament ◽  
Protein Isoforms ◽  
Actin Binding ◽  
Striated Muscles ◽  
C Protein ◽  
Sarcomeric Protein ◽  
Thick Filaments ◽  
Cross Bridges ◽  
Bridge Bearing

C-protein is a 150 kDa protein found within the A bands of all vertebrate cross-striated muscles. By immunoelectron microscopy, it has been demonstrated that C-protein is distributed along a series of 7-9 transverse stripes in the medial, cross-bridge bearing zone of each A band. This zone is now termed the C-zone of the sarcomere. Interest in this protein has been sparked by its striking distribution in the sarcomere: the transverse repeat between C-protein stripes is 43 nm, almost exactly 3 times the 14.3 nm axial repeat of myosin cross-bridges along the thick filaments. The precise packing of C-protein in the thick filament is still unknown. It is the only sarcomeric protein which binds to both myosin and actin, and the actin-binding is Ca-sensitive. In cardiac and slow, but not fast, skeletal muscles C-protein is phosphorylated. Amino acid composition suggests a protein of little or no αhelical content. Variant forms (isoforms) of C-protein have been identified in cardiac, slow and embryonic muscles.

Tissue-specific expression patterns of nuclear receptors

2013 ◽  
Author(s):  
AL Bookout ◽  
Y Jeong ◽  
M Downes ◽  
RT Yu ◽  
RM Evans ◽  
...  
Keyword(s):  
Nuclear Receptors ◽  
Expression Patterns ◽  
Specific Expression ◽  
Tissue Specific ◽  
Tissue Specific Expression

scholarly journals POS0461 RESPONSE TO BIOLOGIC THERAPY IN RHEUMATOID ARTHRITIS: RETHINKING OUR CLASSIFICATION

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 462.1-462
Author(s):  
E. Vallejo-Yagüe ◽  
S. Kandhasamy ◽  
E. Keystone ◽  
A. Finckh ◽  
R. Micheroli ◽  
...  
Keyword(s):  
Treatment Response ◽  
Real World ◽  
Observational Studies ◽  
Initial Response ◽  
Primary Response ◽  
Sustained Response ◽  
Secondary Response ◽  
Real World Data ◽  
World Data ◽  
Secondary Failure

Background:In rheumatoid arthritis (RA), primary failure with biologic treatment may be understood as lack of initial clinical response, while secondary failure would be loss of effectiveness after an initial response. Despite these clinical concepts, there is no unifying operational definition of primary and secondary non-response to RA treatment in observational studies using real-world data. On top of data-driven challenges, when conceptualizing secondary non-responders, it is unclear if the mechanism behind loss of effectiveness after a brief initial response is similar to loss of effectiveness after previous benefit sustained over time.Objectives:This viewpoint aims to motivate discussion on how to define primary and secondary non-response in observational studies. Ultimately, we aim to trigger expert committees to develop standard terminology for these concepts.Methods:We discuss different methodologies for defining primary and secondary non-response in observational studies. To do so, we shortly overview challenges characteristic of performing observational studies in real-world data, and subsequently, we conceptualize whether treatment response should be a dichotomous classification (Primary response/non-response; Secondary response/non-response), or whether one should consider three response categories (Primary response/non-response; Primary sustained/non-sustained response; Secondary response/non-response).Results:RA or biologic registries are a common data source for studying treatment response in real-world data. While registries include disease-specific variables to assess disease progression, missing data, loss of follow-up, and visits restricted to the year or mid-year visit may present a challenge. We believe there is a general agreement to assess primary response within the first 6 month of treatment. However, conceptualizing secondary non-response, one could wonder if a patient with brief initial response and immediate loss of it should belong to the same response category as a patient who relapses after a period of prior benefit that was sustained over time. Until this concern is clarified, we recommend considering a period of sustained response as a pre-requisite for secondary failure. This would result in the following three categories: a) Primary non-response: Lack of response within the first 6 months of treatment; b) Primary sustained response: Maintenance of a positive effectiveness outcome for at least the first 12 months since treatment start; c) Secondary non-response: Loss of effectiveness after achieved primary sustained response. Figure 1 illustrates this classification through a decision tree. Since the underlying mechanisms for treatment failure may differ among the above-mentioned categories, we recommend to use the three-category classification. However, since this may pose additional methodological challenges in real-world data, optionally, a dichotomous 12-month time-point may be used to assess secondary non-response (unfavourable outcome after 12-months) in comparison to primary non-response or non-sustained response (unfavourable outcome within the first 12-months). Similarly, to study primary response, the solely 6-month timepoint may be used.Conclusion:A unified operational definition of treatment response will minimize heterogeneity among observational studies and help improve the ability to draw cross-study comparisons, which we believe would be of particular interest when identifying predictors of treatment failure. Thus, we hope to open the room for discussion and encourage expert committees to work towards a common approach to assess treatment primary and secondary non-response in RA in observational studies.Disclosure of Interests:Enriqueta Vallejo-Yagüe: None declared, Sreemanjari Kandhasamy: None declared, Edward Keystone Speakers bureau: Amgen, AbbVie, F. Hoffmann-La Roche Inc., Janssen Inc., Merck, Novartis, Pfizer Pharmaceuticals, Sanofi Genzyme, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb Company, Celltrion, Myriad Autoimmune, F. Hoffmann-La Roche Inc, Gilead, Janssen Inc, Lilly Pharmaceuticals, Merck, Pfizer Pharmaceuticals, Sandoz, Sanofi-Genzyme, Samsung Bioepsis, Grant/research support from: Amgen, Merck, Pfizer Pharmaceuticals, PuraPharm, Axel Finckh Speakers bureau: Pfizer, Eli-Lilly, Paid instructor for: Pfizer, Eli-Lilly, Consultant of: AbbVie, AB2Bio, BMS, Gilead, Pfizer, Viatris, Grant/research support from: Pfizer, BMS, Novartis, Raphael Micheroli Consultant of: Gilead, Eli-Lilly, Pfizer and Abbvie, Andrea Michelle Burden: None declared

Cognate CD4 help is essential for the reactivation and expansion of CD8 memory T cells directed against the hematopoietic cell–specific dominant minor histocompatibility antigen, H60

Blood ◽  
2009 ◽  
Vol 113 (18) ◽  
pp. 4273-4280 ◽  
Author(s):  
Su Jeong Ryu ◽  
Kyung Min Jung ◽  
Hyun Seung Yoo ◽  
Tae Woo Kim ◽  
Sol Kim ◽  
...  
Keyword(s):  
T Cells ◽  
Cd8 T Cells ◽  
Primary Response ◽  
Hematopoietic Cell ◽  
Secondary Response ◽  
Memory Cd8 T Cells ◽  
Specific Memory ◽  
Cd4 Help ◽  
Different Response

AbstractIn contrast to previous notions of the help-independency of memory CD8 T cells during secondary expansion, here we show that CD4 help is indispensable for the re-expansion of once-helped memory CD8 T cells, using a hematopoietic cell–specific dominant minor histocompatibility (H) antigen, H60, as a model antigen. H60-specific memory CD8 T cells generated during a helped primary response vigorously expanded only when rechallenged under helped conditions. The help requirement for an optimal secondary response was confirmed by a reduction in peak size by CD4 depletion, and was reproduced after skin transplantation. Helpless conditions or noncognate separate help during the secondary response resulted in a significant reduction in the peak size and different response kinetics. Providing CD4 help again during a tertiary challenge restored robust memory expansion; however, the repeated deprivation of help further reduced clonal expansion. Adoptively transferred memory CD8 T cells did not proliferate in CD40L−/− hosts. In the CD40−/− hosts, marginal memory expansion was detected after priming with male H60 cells but was completely abolished by priming with peptide-loaded CD40−/− cells, suggesting the essential role of CD40 and CD40L in memory responses. These results provide insight into the control of minor H antigen-specific CD8 T-cell responses, to maximize the graft-versus-leukemia response.

scholarly journals Tissue Distribution of ACE2 Protein in Syrian Golden Hamster (Mesocricetus auratus) and Its Possible Implications in SARS-CoV-2 Related Studies

2021 ◽  
Vol 11 ◽  
Author(s):  
Voddu Suresh ◽  
Deepti Parida ◽  
Aliva P. Minz ◽  
Manisha Sethi ◽  
Bhabani S. Sahoo ◽  
...  
Keyword(s):  
Expression Pattern ◽  
Golden Hamster ◽  
Expression Patterns ◽  
Mesocricetus Auratus ◽  
Syrian Golden Hamster ◽  
Surface Epithelium ◽  
Specific Expression ◽  
Tissue Specific ◽  
Tissue Specific Expression ◽  
Specific Expression Pattern

The Syrian golden hamster (Mesocricetus auratus) has recently been demonstrated as a clinically relevant animal model for SARS-CoV-2 infection. However, lack of knowledge about the tissue-specific expression pattern of various proteins in these animals and the unavailability of reagents like antibodies against this species hampers these models’ optimal use. The major objective of our current study was to analyze the tissue-specific expression pattern of angiotensin-converting enzyme 2, a proven functional receptor for SARS-CoV-2 in different organs of the hamster. Using two different antibodies (MA5-32307 and AF933), we have conducted immunoblotting, immunohistochemistry, and immunofluorescence analysis to evaluate the ACE2 expression in different tissues of the hamster. Further, at the mRNA level, the expression of Ace2 in tissues was evaluated through RT-qPCR analysis. Both the antibodies detected expression of ACE2 in kidney, small intestine, tongue, and liver. Epithelium of proximal tubules of kidney and surface epithelium of ileum expresses a very high amount of this protein. Surprisingly, analysis of stained tissue sections showed no detectable expression of ACE2 in the lung or tracheal epithelial cells. Similarly, all parts of the large intestine were negative for ACE2 expression. Analysis of tissues from different age groups and sex didn’t show any obvious difference in ACE2 expression pattern or level. Together, our findings corroborate some of the earlier reports related to ACE2 expression patterns in human tissues and contradict others. We believe that this study’s findings have provided evidence that demands further investigation to understand the predominant respiratory pathology of SARS-CoV-2 infection and disease.

Sign in / Sign up

Export Citation Format

Share Document