The heterochronic gene lin-29 encodes a zinc finger protein that controls a terminal differentiation event in Caenorhabditis elegans

Development ◽  
1995 ◽  
Vol 121 (8) ◽  
pp. 2491-2500 ◽  
Author(s):  
A.E. Rougvie ◽  
V. Ambros

A hierarchy of heterochronic genes, lin-4, lin-14, lin-28 and lin-29, temporally restricts terminal differentiation of Caenorhabditis elegans hypodermal seam cells to the final molt. This terminal differentiation event involves cell cycle exit, cell fusion and the differential regulation of genes expressed in the larval versus adult hypodermis. lin-29 is the most downstream gene in the developmental timing pathway and thus it is the most direct known regulator of these diverse processes. We show that lin-29 encodes a protein with five zinc fingers of the (Cys)2-(His)2 class and thus likely controls these processes by regulating transcription in a stage-specific manner. Consistent with this role, a lin-29 fusion protein binds in vitro to the 5′ regulatory sequences necessary in vivo for expression of col-19, a collagen gene expressed in the adult hypodermis. lin-29 mRNA is detected in the first larval stage and increases in abundance through subsequent larval stages until the final molt, when lin-29 activity is required for terminal differentiation.

Development ◽  
1997 ◽  
Vol 124 (21) ◽  
pp. 4333-4342 ◽  
Author(s):  
J.C. Bettinger ◽  
S. Euling ◽  
A.E. Rougvie

Caenorhabditis elegans vulval development culminates during exit from the L4-to-adult molt with the formation of an opening through the adult hypodermis and cuticle that is used for egg laying and mating. Vulva formation requires the heterochronic gene lin-29, which triggers hypodermal cell terminal differentiation during the final molt. lin-29 mutants are unable to lay eggs or mate because no vulval opening forms; instead, a protrusion forms at the site of the vulva. We demonstrate through analysis of genetic mosaics that lin-29 is absolutely required in a small subset of lateral hypodermal seam cells, adjacent to the vulva, for wild-type vulva formation and egg laying. However, lin-29 function is not strictly limited to the lateral hypodermis. First, LIN-29 accumulates in many non-hypodermal cells with known roles in vulva formation or egg laying. Second, animals homozygous for one lin-29 allele, ga94, have the vulval defect and cannot lay eggs, despite having a terminally differentiated adult lateral hypodermis. Finally, vulval morphogenesis and egg laying requires lin-29 activity within the EMS lineage, a lineage that does not generate hypodermal cells.


2002 ◽  
Vol 22 (5) ◽  
pp. 1607-1614 ◽  
Author(s):  
Laura L. Newcomb ◽  
Duane D. Hall ◽  
Warren Heideman

ABSTRACT Transcription of the CLN3 G1 cyclin in Saccharomyces cerevisiae is positively regulated by glucose in a process that involves a set of DNA elements with the sequence AAGAAAAA (A2GA5). To identify proteins that interact with these elements, we used a 1-hybrid approach, which yielded a nuclear zinc finger protein previously identified as Azf1. Gel shift and chromatin immunoprecipitation experiments show that Azf1 binds to the A2GA5 CLN3 regulatory sequences in vitro and in vivo, thus identifying a transcriptional regulatory protein for CLN3 and a DNA sequence target for Azf1. We show that glucose-induced expression of a reporter gene driven by the A2GA5 CLN3 regulatory sequences is dependent upon the presence of AZF1. Furthermore, deletion of AZF1 markedly reduces the transcriptional induction of CLN3 by glucose. In addition, Azf1 can induce reporter expression in a glucose-specific manner when artificially tethered to a promoter via the DNA-binding domain from Gal4. We conclude that AZF1 is a glucose-dependent transcription factor that interacts with the CLN3 A2GA5 repeats to play a positive role in the regulation of CLN3 mRNA expression by glucose.


2018 ◽  
Vol 15 (2) ◽  
pp. 359-365
Author(s):  
Lê Thọ Sơn ◽  
Joohong Ahnn ◽  
Jeong Hoon Cho ◽  
Nguyễn Huy Hoàng

Dicarbonyl/L-xylulose (DCXR) was identified as a dehydrogenase. This type of enzyme was presented in various forms of lives including bacteria, fungi, plants and animals. Generally, it converts L-xylulose to xylitol in the presence of either cofactor NADH or NADPH in vitro. Previous studies reported the biochemistry properties and crystal structure but largely uncovered biological roles of DCXRs. It was impossible to dissect the functions in mice or human cells that had many DCXR homologs in their genomes. Interestingly, the wild-type Caenorhabditis elegans, a well-known model organism in biological research, has only nuclear genomic dhs-21 that encodes a unique homologous DCXR. Thus Ce.dhs-21 and the host C. elegans were relevant for investigation of the physiologically-vital functions of the DCXR. This research aimed to the expression of dhs-21 in vivo. We defined three promoters , manipulated three relative reporter-constructs that conjugated the dhs-21 gene and Green Flouresent Protein (known as GFP) one. The construct vectors were transferred into wild-type C. elegans N2 and as well as the hermaphroditic loss of function dhs-21(jh129) by microinjection. In the results, we found that the expression pattern of dhs-21 under the only p2-promoter construct was stable and similar to immunogold Electric Microscopy (EM) images. The dhs-21 gene was expressed in both sexes of at all larval stages till the deaths of worms. DHS-21 was expressed in the cytosol of the intestinal, gonad sheath and uterous seam cell (utse).


Development ◽  
1995 ◽  
Vol 121 (6) ◽  
pp. 1625-1635 ◽  
Author(s):  
C. Schwartz ◽  
J. Locke ◽  
C. Nishida ◽  
T.B. Kornberg

The cubitus interruptus (ci) gene of Drosophila is expressed in all anterior compartment cells in both embryos and imaginal disks where it encodes a putative zinc-finger protein related to the vertebrate Gli and C. elegans Tra-1 proteins. Using ci/lacZ fusions, we located regulatory sequences responsible for the normal pattern of ci expression, and obtained evidence that separate elements regulate its expression in embryos and imaginal disks. Mutants that delete a portion of this regulatory region express ci ectopically in the posterior compartments of their wing imaginal disks and have wings with malformed posterior compartments. Similar deletions of ci/lacZ fusion constructs also result in ectopic posterior compartment expression. Evidence that the engrailed protein normally represses ci in posterior compartments includes the expansion of ci expression into posterior compartment cells that lack engrailed function, diminution of ci expression upon overexpression of engrailed protein in anterior compartment cells, and the ability of engrailed protein to bind to the ci regulatory region in vivo and in vitro. We suggest that engrailed protein directly represses ci expression in posterior compartment cells.


2021 ◽  
pp. 1-9
Author(s):  
Dayana Torres Valladares ◽  
Sirisha Kudumala ◽  
Murad Hossain ◽  
Lucia Carvelli

Amphetamine is a potent psychostimulant also used to treat attention deficit/hyperactivity disorder and narcolepsy. In vivo and in vitro data have demonstrated that amphetamine increases the amount of extra synaptic dopamine by both inhibiting reuptake and promoting efflux of dopamine through the dopamine transporter. Previous studies have shown that chronic use of amphetamine causes tolerance to the drug. Thus, since the molecular mechanisms underlying tolerance to amphetamine are still unknown, an animal model to identify the neurochemical mechanisms associated with drug tolerance is greatly needed. Here we took advantage of a unique behavior caused by amphetamine in <i>Caenorhabditis elegans</i> to investigate whether this simple, but powerful, genetic model develops tolerance following repeated exposure to amphetamine. We found that at least 3 treatments with 0.5 mM amphetamine were necessary to see a reduction in the amphetamine-induced behavior and, thus, to promote tolerance. Moreover, we found that, after intervals of 60/90 minutes between treatments, animals were more likely to exhibit tolerance than animals that underwent 10-minute intervals between treatments. Taken together, our results show that <i>C. elegans</i> is a suitable system to study tolerance to drugs of abuse such as amphetamines.


1996 ◽  
Vol 16 (6) ◽  
pp. 2977-2986 ◽  
Author(s):  
C Antoniewski ◽  
B Mugat ◽  
F Delbac ◽  
J A Lepesant

The steroid hormone 20-hydroxyecdysone plays a key role in the induction and modulation of morphogenetic events throughout Drosophila development. Previous studies have shown that a heterodimeric nuclear receptor composed of the EcR and USP proteins mediates the action of the hormone at the transcriptional through binding to palindromic ecdysteroid mediates the action of the hormone at the transcriptional level through binding to palindromic ecdysteroid response elements (EcREs) such as those present in the promoter of the hsp27 gene or the fat body-specific enhancer of the Fbp1 gene. We show that in addition to palindromic EcREs, the EcR/USP heterodimer can bind in vitro with various affinities to direct repetitions of the motif AGGTCA separated by 1 to 5 nucleotides (DR1 to DR5), which are known to be target sites for vertebrate nuclear receptors. At variance with the receptors, EcR/USP was also found to bind to a DR0 direct repeat with no intervening nucleotide. In cell transformation assays, direct repeats DR0 to DR5 alone can render the minimum viral tk or Drosophila Fbp1 promoter responsive to 20-hydroxyecdysone, as does the palindromic hsp27 EcRE. In a transgenic assay, however, neither the palindromic hsp27 element nor direct repeat DR3 alone can make the Fbp1 minimal promoter responsive to premetamorphic ecdysteroid peaks. In contrast, DR0 and DR3 elements, when substituted for the natural palindromic EcRE in the context of the Fbp1 enhancer, can drive a strong fat body-specific ecdysteroid response in transgenic animals. These results demonstrate that directly repeated EcR/USP binding sites are as effective as palindromic EcREs in vivo. They also provide evidence that additional flanking regulatory sequences are crucially required to potentiate the hormonal response mediated by both types of elements and specify its spatial and temporal pattern.


1993 ◽  
Vol 13 (9) ◽  
pp. 5710-5724
Author(s):  
E DesJardins ◽  
N Hay

Transcription of the human proto-oncogene c-myc is governed by two tandem principal promoters, termed P1 and P2. In general, the downstream promoter, P2, is predominant, which is in contrast to the promoter occlusion phenomenon usually observed in genes containing tandem promoters. A shift in human c-myc promoter usage has been observed in some tumor cells and in certain physiological conditions. However, the mechanisms that regulate promoter usage are not well understood. The present studies identify regulators which are required to promote transcription from both human c-myc promoters, P1 and P2, and have a role in determining their relative activities in vivo. A novel regulatory region located 101 bp upstream of P1 was characterized and contains five tandem repeats of the consensus sequence CCCTCCCC (CT element). The integrity of the region containing all five elements is required to promote transcription from P1 and for maximal activity from P2 in vivo. A single copy of this same element, designated CT-I2, also appears in an inverted orientation 53 bp upstream of the P2 transcription start site. This element has an inhibitory effect on P1 transcription and is required for P2 transcription. The transcription factor Sp1 was identified as the factor that binds specifically to the tandem CT elements upstream of P1 and to the CT-I2 element upstream of P2. In addition, the recently cloned zinc finger protein ZF87, or MAZ, was also able to bind these same elements in vitro. The five tandem CT elements can be functionally replaced by a heterologous enhancer that only in the absence of CT-I2 reverses the promoter usage, similar to what is observed in the translocated c-myc allele of Burkitt's lymphoma cells.


1986 ◽  
Vol 6 (12) ◽  
pp. 4548-4557
Author(s):  
J Hirsh ◽  
B A Morgan ◽  
S B Scholnick

We delimited sequences necessary for in vivo expression of the Drosophila melanogaster dopa decarboxylase gene Ddc. The expression of in vitro-altered genes was assayed following germ line integration via P-element vectors. Sequences between -209 and -24 were necessary for normally regulated expression, although genes lacking these sequences could be expressed at 10 to 50% of wild-type levels at specific developmental times. These genes showed components of normal developmental expression, which suggests that they retain some regulatory elements. All Ddc genes lacking the normal immediate 5'-flanking sequences were grossly deficient in larval central nervous system expression. Thus, this upstream region must contain at least one element necessary for this expression. A mutated Ddc gene without a normal TATA boxlike sequence used the normal RNA start points, indicating that this sequences is not required for start point specificity.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jain Jeong ◽  
Soyoung Jang ◽  
Song Park ◽  
Wookbong Kwon ◽  
Si-Yong Kim ◽  
...  

Abstract Background Juxtaposed with another zinc finger protein 1 (JAZF1) is associated with metabolic disorders, including type 2 diabetes mellitus (T2DM). Several studies showed that JAZF1 and body fat mass are closely related. We attempted to elucidate the JAZF1 functions on adipose development and related metabolism using in vitro and in vivo models. Results The JAZF1 expression was precisely regulated during adipocyte differentiation of 3T3-L1 preadipocyte and mouse embryonic fibroblasts (MEFs). Homozygous JAZF1 deletion (JAZF1-KO) resulted in impaired adipocyte differentiation in MEF. The JAZF1 role in adipocyte differentiation was demonstrated by the regulation of PPARγ—a key regulator of adipocyte differentiation. Heterozygous JAZF1 deletion (JAZF1-Het) mice fed a normal diet (ND) or a high-fat diet (HFD) had less adipose tissue mass and impaired glucose homeostasis than the control (JAZF1-Cont) mice. However, other metabolic organs, such as brown adipose tissue and liver, were negligible effect on JAZF1 deficiency. Conclusion Our findings emphasized the JAZF1 role in adipocyte differentiation and related metabolism through the heterozygous knockout mice. This study provides new insights into the JAZF1 function in adipose development and metabolism, informing strategies for treating obesity and related metabolic disorders.


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