A cyclic AMP-responsive element-binding transcriptional activator in Drosophila melanogaster, dCREB-A, is a member of the leucine zipper family

1992 ◽  
Vol 12 (9) ◽  
pp. 4123-4131
Author(s):  
S M Smolik ◽  
R E Rose ◽  
R H Goodman

In this report, we describe the isolation and initial characterization of a Drosophila protein, dCREB-A, that can bind the somatostatin cyclic AMP (cAMP)-responsive element and is capable of activating transcription in cell culture. Sequence analysis demonstrates that this protein is a member of the leucine zipper family of transcription factors. dCREB-A is unusual in that it contains six hydrophobic residue iterations in the zipper domain rather than the four or five commonly found in this group of proteins. The DNA-binding domain is more closely related to mammalian CREB than to the AP-1 factors in both sequence homology and specificity of cAMP-responsive element binding. In embryos, dCREB-A is expressed in the developing salivary gland. A more complex pattern of expression is detected in the adult; transcripts are found in the brain and optic lobe cell bodies, salivary gland, and midgut epithelial cells of the cardia. In females, dCREB-A is expressed in the ovarian columnar follicle cells, and in males, dCREB-A RNA is seen in the seminal vesicle, ejaculatory duct, and ejaculatory bulb. These results suggest that the dCREB-A transcription factor may be involved in fertility and neurological functions.

1992 ◽  
Vol 12 (9) ◽  
pp. 4123-4131 ◽  
Author(s):  
S M Smolik ◽  
R E Rose ◽  
R H Goodman

In this report, we describe the isolation and initial characterization of a Drosophila protein, dCREB-A, that can bind the somatostatin cyclic AMP (cAMP)-responsive element and is capable of activating transcription in cell culture. Sequence analysis demonstrates that this protein is a member of the leucine zipper family of transcription factors. dCREB-A is unusual in that it contains six hydrophobic residue iterations in the zipper domain rather than the four or five commonly found in this group of proteins. The DNA-binding domain is more closely related to mammalian CREB than to the AP-1 factors in both sequence homology and specificity of cAMP-responsive element binding. In embryos, dCREB-A is expressed in the developing salivary gland. A more complex pattern of expression is detected in the adult; transcripts are found in the brain and optic lobe cell bodies, salivary gland, and midgut epithelial cells of the cardia. In females, dCREB-A is expressed in the ovarian columnar follicle cells, and in males, dCREB-A RNA is seen in the seminal vesicle, ejaculatory duct, and ejaculatory bulb. These results suggest that the dCREB-A transcription factor may be involved in fertility and neurological functions.


Neuroreport ◽  
2000 ◽  
Vol 11 (11) ◽  
pp. 2577-2579 ◽  
Author(s):  
Subhash C. Pandey ◽  
Navdha Mittal ◽  
Alcino J. Silva

1996 ◽  
Vol 16 (5) ◽  
pp. 2174-2182 ◽  
Author(s):  
F Bantignies ◽  
R Rousset ◽  
C Desbois ◽  
P Jalinot

To achieve a better understanding of the mechanism of transactivation by Tax of human T-cell leukemia virus type 1 Tax-responsive element 1 (TRE-1), we developed a genetic approach with Saccharomyces cerevisiae. We constructed a yeast reporter strain containing the lacZ gene under the control of the CYC1 promoter associated with three copies of TRE-1. Expression of either the cyclic AMP response element-binding protein (CREB) or CREB fused to the GAL4 activation domain (GAD) in this strain did not modify the expression of the reporter gene. Tax alone was also inactive. However, expression of the reporter gene was induced by coexpression of Tax and CREB. This effect was stronger with the GAD-CREB fusion protein. Analysis of different CREB mutants with this genetic system indicated that the C-terminal 92 amino acid residues, which include the basic domain and the leucine zipper, are necessary and sufficient to mediate transactivation by Tax. To identify cellular proteins binding to TRE-1 in a Tax-dependent manner, this strain was also used to screen a library of human cDNAs fused to GAD. Of five positive clones isolated from 0.75 x 10(6) yeast colonies, four were members of the CREB/activating transcription factor (ATF) family: CREB, two isoforms of the cyclic AMP-responsive element modulator (CREM), and ATF-1. Interestingly, these three proteins can be phosphorylated by protein kinase A and thus form a particular subgroup within the CREB/ATF family. Expression of ATF-2 in S. cerevisiae did not activate TRE-1 in the presence of Tax. This shows that in a eukaryotic nucleus, Tax specifically interacts with the basic domain-leucine zipper region of ATF-1, CREB, and CREM. The fifth clone identified in this screening corresponded to the Ku autoantigen p70 subunit. When fused to GAD, the C-terminal region of Ku was able to activate transcription via TRE-1 but this activation was not dependent on Tax.


1981 ◽  
Vol 197 (3) ◽  
pp. 767-770 ◽  
Author(s):  
H Duve ◽  
A Thorpe ◽  
R Neville ◽  
N R Lazarus

Using 10(6) flies (5 kg of heads) a pancreatic polypeptide-like material has been partially purified from the blowfly Calliphora vomitoria. The isolated material was eluted on Sephadex G-50 similarly to bovine pancreatic polypeptide and had an RF on polyacrylamide-gel electrophoresis that was identical with that of the bovine hormone. The material diluted linearly and showed parallelism with bovine standards in a bovine pancreatic polypeptide immunoassay. In specificity controls the immunoreactivity was not abolished by trasylol and no cross-reactivity was discerned in assay for glucagon, proangiotensin and cyclic AMP. These data suggest that the pancreatic polypeptide material in the brain of the blowfly has close structural similarity to the mammalian hormone.


Author(s):  
D. E. Philpott ◽  
A. Takahashi

Two month, eight month and two year old rats were treated with 10 or 20 mg/kg of E. Coli endotoxin I. P. The eight month old rats proved most resistant to the endotoxin. During fixation the aorta, carotid artery, basil arartery of the brain, coronary vessels of the heart, inner surfaces of the heart chambers, heart and skeletal muscle, lung, liver, kidney, spleen, brain, retina, trachae, intestine, salivary gland, adrenal gland and gingiva were treated with ruthenium red or alcian blue to preserve the mucopolysaccharide (MPS) coating. Five, 8 and 24 hrs of endotoxin treatment produced increasingly marked capillary damage, disappearance of the MPS coating, edema, destruction of endothelial cells and damage to the basement membrane in the liver, kidney and lung.


Author(s):  
Amal Alzain ◽  
Suhaib Alameen ◽  
Rani Elmaki ◽  
Mohamed E. M. Gar-Elnabi

This study concern to characterize the brain tissues to ischemic stroke, gray matter, white matter and CSF using texture analysisto extract classification features from CT images. The First Order Statistic techniques included sevenfeatures. To find the gray level variation in CT images it complements the FOS features extracted from CT images withgray level in pixels and estimate the variation of thesubpatterns. analyzing the image with Interactive Data Language IDL software to measure the grey level of images. The results show that the Gray Level variation and   features give classification accuracy of ischemic stroke 97.6%, gray matter95.2%, white matter 97.3% and the CSF classification accuracy 98.0%. The overall classification accuracy of brain tissues 97.0%.These relationships are stored in a Texture Dictionary that can be later used to automatically annotate new CT images with the appropriate brain tissues names.


Author(s):  
Stefano Vassanelli

Establishing direct communication with the brain through physical interfaces is a fundamental strategy to investigate brain function. Starting with the patch-clamp technique in the seventies, neuroscience has moved from detailed characterization of ionic channels to the analysis of single neurons and, more recently, microcircuits in brain neuronal networks. Development of new biohybrid probes with electrodes for recording and stimulating neurons in the living animal is a natural consequence of this trend. The recent introduction of optogenetic stimulation and advanced high-resolution large-scale electrical recording approaches demonstrates this need. Brain implants for real-time neurophysiology are also opening new avenues for neuroprosthetics to restore brain function after injury or in neurological disorders. This chapter provides an overview on existing and emergent neurophysiology technologies with particular focus on those intended to interface neuronal microcircuits in vivo. Chemical, electrical, and optogenetic-based interfaces are presented, with an analysis of advantages and disadvantages of the different technical approaches.


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