CLAMP directly interacts with MSL2 to facilitate Drosophila dosage compensation

AbstractThe binding of Drosophila male-specific lethal (MSL) dosage compensation complex exclusively to male X chromosome provides an excellent model system to understand mechanisms of selective recruitment of protein complexes to chromatin. Previous studies showed that the male-specific organizer of the complex, MSL2, and ubiquitous DNA-binding protein CLAMP are key players in the specificity of X chromosome binding. The CXC domain of MSL2 binds to genomic sites of MSL complex recruitment. Here we demonstrated that MSL2 directly interacts with the N-terminal zinc-finger domain of CLAMP. CLAMP-MSL2 and CXC-DNA interactions are cooperatively involved in recruitment of MSL complex to the X chromosome.

Download Full-text

Jil-1, a Chromosomal Kinase Implicated in Regulation of Chromatin Structure, Associates with the Male Specific Lethal (Msl) Dosage Compensation Complex

The Journal of Cell Biology ◽

10.1083/jcb.149.5.1005 ◽

2000 ◽

Vol 149 (5) ◽

pp. 1005-1010 ◽

Cited By ~ 92

Author(s):

Ye Jin ◽

Yanming Wang ◽

Jørgen Johansen ◽

Kristen M. Johansen

Keyword(s):

Signal Transduction ◽

X Chromosome ◽

Dosage Compensation ◽

Chromatin Structure ◽

Ectopic Expression ◽

Signal Transduction Pathways ◽

Dosage Compensation Complex ◽

Male Specific Lethal ◽

Msl Complex ◽

Male Specific

JIL-1 is a novel chromosomal kinase that is upregulated almost twofold on the male X chromosome in Drosophila. Here we demonstrate that JIL-1 colocalizes and physically interacts with male specific lethal (MSL) dosage compensation complex proteins. Furthermore, ectopic expression of the MSL complex directed by MSL2 in females causes a concomitant upregulation of JIL-1 to the female X that is abolished in msl mutants unable to assemble the complex. Thus, these results strongly indicate JIL-1 associates with the MSL complex and further suggests JIL-1 functions in signal transduction pathways regulating chromatin structure.

Download Full-text

Painting of Fourth and the X-Linked 1.688 Satellite in D. melanogaster Is Involved in Chromosome-Wide Gene Regulation

Cells ◽

10.3390/cells9020323 ◽

2020 ◽

Vol 9 (2) ◽

pp. 323

Author(s):

Samaneh Ekhteraei-Tousi ◽

Jacob Lewerentz ◽

Jan Larsson

Keyword(s):

X Chromosome ◽

Dosage Compensation ◽

Rapid Evolution ◽

Regulatory Mechanisms ◽

Expression Of Genes ◽

Male Specific Lethal ◽

Msl Complex ◽

Specific Regulation ◽

Male Specific ◽

Genomic Regions

Chromosome-specific regulatory mechanisms provide a model to understand the coordinated regulation of genes on entire chromosomes or on larger genomic regions. In fruit flies, two chromosome-wide systems have been characterized: The male-specific lethal (MSL) complex, which mediates dosage compensation and primarily acts on the male X-chromosome, and Painting of fourth (POF), which governs chromosome-specific regulation of genes located on the 4th chromosome. How targeting of one specific chromosome evolves is still not understood; but repeated sequences, in forms of satellites and transposable elements, are thought to facilitate the evolution of chromosome-specific targeting. The highly repetitive 1.688 satellite has been functionally connected to both these systems. Considering the rapid evolution and the necessarily constant adaptation of regulatory mechanisms, such as dosage compensation, we hypothesised that POF and/or 1.688 may still show traces of dosage-compensation functions. Here, we test this hypothesis by transcriptome analysis. We show that loss of Pof decreases not only chromosome 4 expression but also reduces the X-chromosome expression in males. The 1.688 repeat deletion, Zhr1 (Zygotic hybrid rescue), does not affect male dosage compensation detectably; however, Zhr1 in females causes a stimulatory effect on X-linked genes with a strong binding affinity to the MSL complex (genes close to high-affinity sites). Lack of pericentromeric 1.688 also affected 1.688 expression in trans and was linked to the differential expression of genes involved in eggshell formation. We discuss our results with reference to the connections between POF, the 1.688 satellite and dosage compensation, and the role of the 1.688 satellite in hybrid lethality.

Download Full-text

Absence of X-chromosome dosage compensation in the primordial germ cells of Drosophila embryos

Scientific Reports ◽

10.1038/s41598-021-84402-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ryoma Ota ◽

Makoto Hayashi ◽

Shumpei Morita ◽

Hiroki Miura ◽

Satoru Kobayashi

Keyword(s):

X Chromosome ◽

Germ Cells ◽

Dosage Compensation ◽

Sex Chromosome ◽

Primordial Germ Cells ◽

Histone H4 ◽

X Chromosomes ◽

Essential Components ◽

Msl Complex ◽

Male Specific

AbstractDosage compensation is a mechanism that equalizes sex chromosome gene expression between the sexes. In Drosophila, individuals with two X chromosomes (XX) become female, whereas males have one X chromosome (XY). In males, dosage compensation of the X chromosome in the soma is achieved by five proteins and two non-coding RNAs, which assemble into the male-specific lethal (MSL) complex to upregulate X-linked genes twofold. By contrast, it remains unclear whether dosage compensation occurs in the germline. To address this issue, we performed transcriptome analysis of male and female primordial germ cells (PGCs). We found that the expression levels of X-linked genes were approximately twofold higher in female PGCs than in male PGCs. Acetylation of lysine residue 16 on histone H4 (H4K16ac), which is catalyzed by the MSL complex, was undetectable in these cells. In male PGCs, hyperactivation of X-linked genes and H4K16ac were induced by overexpression of the essential components of the MSL complex, which were expressed at very low levels in PGCs. Together, these findings indicate that failure of MSL complex formation results in the absence of X-chromosome dosage compensation in male PGCs.

Download Full-text

The msl-2 dosage compensation gene of Drosophila encodes a putative DNA-binding protein whose expression is sex specifically regulated by Sex-lethal

Development ◽

10.1242/dev.121.10.3245 ◽

1995 ◽

Vol 121 (10) ◽

pp. 3245-3258 ◽

Cited By ~ 6

Author(s):

G.J. Bashaw ◽

B.S. Baker

Keyword(s):

Dna Binding ◽

X Chromosome ◽

Dosage Compensation ◽

Ring Finger ◽

The Other ◽

Male Specific Lethal ◽

Alternatively Spliced ◽

Sex Lethal ◽

Specific Regulation ◽

Male Specific

In Drosophila dosage compensation increases the rate of transcription of the male's X chromosome and depends on four autosomal male-specific lethal genes. We have cloned the msl-2 gene and shown that MSL-2 protein is co-localized with the other three MSL proteins at hundreds of sites along the male polytene X chromosome and that this binding requires the other three MSL proteins. msl-2 encodes a protein with a putative DNA-binding domain: the RING finger. MSL-2 protein is not produced in females and sequences in both the 5′ and 3′ UTRs are important for this sex-specific regulation. Furthermore, msl-2 pre-mRNA is alternatively spliced in a Sex-lethal-dependent fashion in its 5′ UTR.

Download Full-text

Drosophila Male-Specific Lethal 2 Protein Controls Sex-Specific Expression of the roX Genes

Genetics ◽

10.1093/genetics/166.4.1825 ◽

2004 ◽

Vol 166 (4) ◽

pp. 1825-1832 ◽

Cited By ~ 1

Author(s):

Barbara P Rattner ◽

Victoria H Meller

Keyword(s):

Gene Expression ◽

Transcriptional Regulation ◽

X Chromosome ◽

Specific Expression ◽

Linked Gene ◽

Male And Female ◽

Male Specific Lethal ◽

Msl Complex ◽

Male Specific ◽

Rox Rna

Abstract The MSL complex of Drosophila upregulates transcription of the male X chromosome, equalizing male and female X-linked gene expression. Five male-specific lethal proteins and at least one of the two noncoding roX RNAs are essential for this process. The roX RNAs are required for the localization of MSL complexes to the X chromosome. Although the mechanisms directing targeting remain speculative, the ratio of MSL protein to roX RNA influences localization of the complex. We examine the transcriptional regulation of the roX genes and show that MSL2 controls male-specific roX expression in the absence of any other MSL protein. We propose that this mechanism maintains a stable MSL/roX ratio that is favorable for localization of the complex to the X chromosome.

Download Full-text

Drosophila CLAMP is an essential protein with sex-specific roles in males and females

10.1101/042820 ◽

2016 ◽

Author(s):

Jennifer A. Urban ◽

Caroline A. Doherty ◽

William T. Jordan ◽

Jacob E. Bliss ◽

Jessica Feng ◽

...

Keyword(s):

X Chromosome ◽

Dosage Compensation ◽

Zinc Finger Protein ◽

Pericentric Heterochromatin ◽

Single Male ◽

Essential Protein ◽

Msl Complex ◽

Males And Females ◽

Male Specific

AbstractDosage compensation is a fundamental mechanism in many species that corrects for the inherent imbalance in X-chromosome copy number between XY males and XX females. In Drosophila melanogaster, transcriptional output from the single male X-chromosome is equalized to that of XX females by recruitment of the Male Specific Lethal (MSL) complex to specific sequences along the length of the X-chromosome. The initial recruitment of MSL complex to the X-chromosome is dependent on a recently discovered zinc finger protein called Chromatin-Linked Adapter for MSL Proteins (CLAMP). However, further studies on the in vivo function of CLAMP remained difficult because the location of the gene in pericentric heterochromatin made it challenging to create null mutations or deficiencies. Using the CRISPR/Cas9 genome editing system, we generated the first null mutant in the clamp gene that eliminates expression of CLAMP protein. We show that CLAMP is necessary for both male and female viability. While females die at the third instar larval stage, males die earlier, likely due to the essential role of CLAMP in male dosage compensation. Moreover, we demonstrate that CLAMP promotes dosage compensation in males and represses key male-specific transcripts involved in sex-determination in females. Our results reveal that CLAMP is an essential protein with dual roles in males and females, which together assure that dosage compensation is a sex-specific process.

Download Full-text

Rapid Evolution of Autosomal Binding Sites of the Dosage Compensation Complex in Drosophila melanogaster and Its Association With Transcription Divergence

Frontiers in Genetics ◽

10.3389/fgene.2021.675027 ◽

2021 ◽

Vol 12 ◽

Author(s):

Aimei Dai ◽

Yushuai Wang ◽

Anthony Greenberg ◽

Zhongqi Liufu ◽

Tian Tang

Keyword(s):

Drosophila Melanogaster ◽

Dosage Compensation ◽

Binding Sites ◽

Protein Sequence ◽

Rapid Evolution ◽

Close Relative ◽

Sequence Evolution ◽

Male Specific Lethal ◽

Msl Complex ◽

Male Specific

How pleiotropy influences evolution of protein sequence remains unclear. The male-specific lethal (MSL) complex in Drosophila mediates dosage compensation by 2-fold upregulation of the X chromosome in males. Nevertheless, several MSL proteins also bind autosomes and likely perform functions not related to dosage compensation. Here, we study the evolution of MOF, MSL1, and MSL2 biding sites in Drosophila melanogaster and its close relative Drosophila simulans. We found pervasive expansion of the MSL binding sites in D. melanogaster, particularly on autosomes. The majority of these newly-bound regions are unlikely to function in dosage compensation and associated with an increase in expression divergence between D. melanogaster and D. simulans. While dosage-compensation related sites show clear signatures of adaptive evolution, these signatures are even more marked among autosomal regions. Our study points to an intriguing avenue of investigation of pleiotropy as a mechanism promoting rapid protein sequence evolution.

Download Full-text

Evidence that MSL-mediated dosage compensation in Drosophila begins at blastoderm

Development ◽

10.1242/dev.122.9.2751 ◽

1996 ◽

Vol 122 (9) ◽

pp. 2751-2760 ◽

Cited By ~ 1

Author(s):

A. Franke ◽

A. Dernburg ◽

G.J. Bashaw ◽

B.S. Baker

Keyword(s):

X Chromosome ◽

Dosage Compensation ◽

Dependent Manner ◽

Gene Products ◽

Histone H4 ◽

Single Male ◽

Somatic Tissues ◽

Male Specific Lethal ◽

Male Specific ◽

Blastoderm Stage

In Drosophila equalization of the amounts of gene products produced by X-linked genes in the two sexes is achieved by hypertranscription of the single male X chromosome. This process, dosage compensation, is controlled by a set of male-specific lethal (msl) genes, that appear to act at the level of chromatin structure. The properties of the MSL proteins have been extensively studied in the polytene salivary gland chromosomes where they bind to the same set of sites along the male X chromosome in a co-dependent manner. Here we report experiments that show that the MSL proteins first associate with the male X chromosome as early as blastoderm stage, slightly earlier than the histone H4 isoform acetylated at lysine 16 is detected on the X chromosome. MSL binding to the male X chromosome is observed in all somatic tissues of embryos and larvae. Binding of the MSLs to the X chromosome is also interdependent in male embryos and prevented in female embryos by the expression of Sex-lethal (Sxl). A delayed onset of binding of the MSLs in male progeny of homozygous mutant msl-1 or mle mothers coupled with the previous finding that such males have an earlier lethal phase supports the idea that msl-mediated dosage compensation begins early in embryogenesis. Other results show that the maleless (MLE) protein on embryo and larval chromosomes differs in its reactivity with antibodies; the functional significance of this finding remains to be explored.

Download Full-text