Biology subjects

Azlan, A.

Publications and source records attributed to Azlan, A..

9 recordsLinked to original sources

bioRxiv2025

MYCBP interacts with Sakura and Otu and is essential for germline stem cell renewal and differentiation and oogenesis

The self-renewal and differentiation of germline stem cells (GSCs) are tightly regulated during oogenesis. The Drosophila female germline provides a powerful model to study these regulatory mechanisms. We previously identified Sakura (also known as Bourbon/CG14545) as a crucial factor for maintenance and differentiation of GSCs and oogenesis, and demonstrated that Sakura binds to Ovarian Tumor (Otu), another essential regulator of these processes. Here, we identify MYCBP (c-Myc binding protein) as an additional essential component of this regulatory network. We show that MYCBP physically associates with itself, Sakura, and Otu, forming binary and ternary complexes including a MYCBP*Sakura*Otu complex. MYCBP is highly expressed in the ovary, and mycbp null mutant females exhibit rudimentary ovaries with germline-less and tumorous ovarioles, fail to produce eggs, and are completely sterile. Germline-specific depletion of mycbp disrupts Dpp/BMP signaling, causing aberrant expression of bag-of-marbles (bam) and leading to defective differentiation and GSC loss. In addition, mycbp is required for female-specific splicing of sex-lethal (sxl), a master regulator of sex identity determination. These phenotypes closely resemble those observed those of sakura and otu mutants. Together, our findings reveal that MYCBP functions in concert with Sakura and Otu to coordinate self-renewal and differentiation of GSCs and oogenesis in Drosophila.

developmental biology↗

bioRxiv2024

Female-germline specific protein Sakura interacts with Otu and is crucial for germline stem cell renewal and differentiation and oogenesis

During oogenesis, self-renewal and differentiation of germline stem cells (GSCs) must be tightly regulated. The Drosophila female germline serves as an excellent model for studying these regulatory mechanisms. Here, we report that a previously uncharacterized gene CG14545, which we named sakura, is essential for oogenesis and female fertility in Drosophila. Sakura is predominantly expressed in the ovaries, particularly in the germline cells, including GSCs. sakura null mutant female flies display rudimentary ovaries with germline-less and tumorous phenotypes, fail to produce eggs, and are completely sterile. The germline-specific depletion of sakura impairs Dpp/BMP signaling, leading to aberrant bag-of-marbles (bam) expression, resulting in faulty differentiation and loss of GSCs. sakura is also necessary for normal levels of piwi-interacting RNAs (piRNAs) levels and for female-specific splicing of sex-lethal (sxl), a master regulator of sex identity determination. We identified Ovarian Tumor (Otu) as a protein binding partner of Sakura and found that loss of otu phenocopies loss of sakura in ovaries. Thus, we identify Sakura as a crucial factor for GSC renewal and differentiation and oogenesis, and propose that Sakura and Otu function together in these processes.

genetics↗

bioRxiv2021

Dual inhibition of anti-apoptotic proteins BCL-XL and MCL-1 enhances cytotoxicity of Nasopharyngeal carcinoma cells.

One of the many strategies that cancer cells use to evade cell death is through upregulation of the BCL-2 anti-apoptotic proteins. Hence, these proteins have become attractive therapeutic targets. Given that different cell population rely on different anti-apoptotic proteins for survival, it is crucial to determine which proteins are important for NPC survival. Here we determined the survival requirements for the NPC cells using combination of CRISPR/Cas9 technique and pharmacological approaches. A human apoptosis RT2 Profiler PCR Array was first employed to profile the anti-apoptotic gene expressions in NPC cell lines HK-1 and C666-1. The HK-1 cells expressed all the anti-apoptotic genes (MCL-1, BFL-1, BCL-2, BCL-XL, and BCL-w). Similarly, the C666-1 cells expressed all the anti-apoptotic proteins except BFL-1 (undetectable level). Notably, both cell lines highly expressed MCL-1. Deletion of MCL-1 sensitized cells to A-1331852 suggesting that MCL-1 and BCL-XL may be important for NPC cell survival. Co-inhibition of MCL-1 and BCL-2 with MCL-1 selective inhibitor S63845 and BCL-2 selective inhibitor ABT-199 inhibited NPC cell proliferation but the effect on cell viability was more profound with co-inhibition of MCL-1 and BCL-XL with S63845 and A-1331852, implying that MCL-1 and BCL-XL are crucial for NPC cell survival. Furthermore, co-inhibition of MCL-1 and BCL-XL inhibited the growth and invasion of NPC spheroids. Deletion of BFL-1 sensitized cells to A-1331852 suggesting that BFL-1 may play a role in NPC cell survival. Taken together co-inhibition of BCL-XL and MCL-1/BFL-1 could be potential treatment strategies for NPC.

cancer biology↗

bioRxiv2020

Genome-wide identification of Aedes albopictus long noncoding RNAs and their association with dengue and zika virus infection

The Asian tiger mosquito, Aedes albopictus (Ae. albopictus), is an important vector that transmits arboviruses such as dengue (DENV), Zika (ZIKV) and Chikungunya virus (CHIKV). On the other hand, long noncoding RNAs (lncRNAs) are known to regulate various biological processes. Knowledge on Ae. albopictus lncRNAs and their functional role in virus-host interactions are still limited. Here, we identified and characterized the lncRNAs in the genome of an arbovirus vector, Ae. albopictus, and evaluated their potential involvement in DENV and ZIKV infection. We used 148 public datasets, and identified a total of 10, 867 novel lncRNA transcripts, of which 5,809, 4,139, and 919 were intergenic, intronic and antisense respectively. The Ae. albopictus lncRNAs shared many characteristics with other species such as short length, low GC content, and low sequence conservation. RNA-sequencing of Ae. albopictus cells infected with DENV and ZIKV showed that the expression of lncRNAs was altered upon virus infection. Target prediction analysis revealed that Ae. albopictus lncRNAs may regulate the expression of genes involved in immunity and other metabolic and cellular processes. To verify the role of lncRNAs in virus infection, we generated mutation in lncRNA loci using CRISPR-Cas9, and discovered that two lncRNA loci mutations, namely XLOC_029733 (novel lncRNA transcript id: lncRNA_27639.2) and LOC115270134 (known lncRNA transcript id: XR_003899061.1) resulted in enhancement of DENV and ZIKV replication. The results presented here provide an important foundation for future studies of lncRNAs and their relationship with virus infection in Ae. albopictus. Author summaryAe. albopictus is an important vector of arboviruses such as dengue and Zika. Studies on virus-host interaction at gene expression and molecular level are crucial especially in devising methods to inhibit virus replication in Aedes mosquito. Previous reports showed that, besides protein-coding genes, noncoding RNAs such as lncRNAs are also involved in virus-host interaction. In this study, we report a comprehensive catalog of novel lncRNA transcripts in the genome of Ae. albopictus. We also show that the expression of lncRNAs was altered upon infection with dengue and Zika. Additionally, depletion of certain lncRNAs resulted in increased replication of dengue and Zika; hence, suggesting potential association of lncRNAs in virus infection. Results of this study provide a new avenue to the investigation of mosquito-virus interactions that may potentially pave way to the development of novel methods in vector control.

genetics↗

bioRxiv2020

Transcriptomic response of an Antarctic yeast Rhodotorula sp. USM-PSY62 to temperature changes

Rhodotorula sp. (USM-PSY62) is a psychrophilic yeast isolated from Antarctic sea ice and it grows optimally at 15 {degrees}C. This study was set up to observe how USM-PSY62 adapted to fluctuations in temperature. During cold adaptation, an elevated transcription of the CorA magnesium transporter gene in USM-PSY62 indicated a higher requirement for magnesium ions in order to gain additional enzyme cofactors or maintain cytoplasmic fluidity. The HepA homologue coding for DNA/RNA helicase was also over-expressed in cold condition possibly to reorganize secondary structures of DNA and RNA. An up-regulation of the catalase gene was also observed reflecting an increment in the concentration of reactive oxygen species and fluctuations in the associated antioxidant system. The YOP1 gene, which encodes a membrane protein associated with protein transport and membrane traffic, was the most down-regulated under cold shock condition. The genes responsible for the structural maintenance of chromosome (SMC) were also down-regulated when the temperature was shifted to 0 {degrees}C. Upon cold shock, the gene for heat shock factor protein 1 (HSF1) was also down-regulated. Hsf1 is a transcriptional regulator which regulate the heat shock responses. Although USM-PSY62 showed some common adaptive strategies as in several other psychrophilic organisms, new mechanisms were also uncovered.

bioinformatics↗

bioRxiv2020

Identification and characterization of long noncoding RNAs and their association with acquisition of blood meal in Culex quinquefasciatus

The Southern house mosquito, Culex quinquefasciatus (Cx. quinquefasciatus) is an important vector that transmit multiple diseases including West Nile encephalitis, Japanese encephalitis, St. Louis encephalitis and lymphatic filariasis. Long noncoding RNAs (lncRNAs) involve in many biological processes such development, infection, and virus-host interaction. However, there is no systematic identification and characterization of lncRNAs in Cx. quinquefasciatus. Here, we report the first ever lncRNA identification in Cx. quinquefasciatus. By using 31 public RNA-seq datasets, a total of 4,763 novel lncRNA transcripts were identified, of which 3,591, 569, and 603 were intergenic, intronic, and antisense respectively. Examination of genomic features revealed that Cx. quinquefasciatus shared similar characteristics with other species such as short in length, low GC content, low sequence conservation, and low coding potential. Furthermore, compared to protein-coding genes, Cx. quinquefasciatus lncRNAs had lower expression values, and tended to be expressed in temporally-specific fashion. In addition, weighted correlation network and functional annotation analyses showed that lncRNAs may have roles in blood meal acquisition of adult female Cx. quinquefasciatus mosquitoes. This study presents the first systematic identification and analysis of Cx. quinquefasciatus lncRNAs and their association with blood feeding. Results generated from this study will facilitate future investigation on the function of Cx. quinquefasciatus lncRNAs.

genomics↗

bioRxiv2020

Revised annotation and characterization of novel Aedes albopictus miRNAs and their potential functions in dengue virus infection

The Asian tiger mosquito, Aedes albopictus (Ae. albopictus), is a highly invasive species that transmit several arboviruses including dengue (DENV), Zika (ZIKV), and chikungunya (CHIKV). Although several studies have identified microRNAs (miRNAs) in Ae. albopictus, it is crucial to extend and improve current annotations with the newly improved genome assembly, and the increase number of small RNA-sequencing data. We combined our high-depth sequence data and 26 public datasets to re-annotate Ae. albopictus miRNAs, and found a total of 110 novel mature miRNAs. We discovered that the expression of novel miRNAs was lower than known miRNAs. Furthermore, compared to known miRNAs, novel miRNAs are prone to be expressed in stage-specific manner. Upon DENV infection, a total of 59 novel miRNAs were differentially expressed, and target prediction analysis revealed that miRNA-target genes were involved in lipid metabolism and protein processing in endoplasmic reticulum. Taken together, miRNA annotation profile provided here is the most comprehensive to date, and we believed that this will facilitate future research in understanding virus-host interactions particularly on the role of miRNAs.

genomics↗

bioRxiv2018

Identification and characterization of Aedes albopictus long noncoding RNAs provides insights into their roles in development and flavivirus infection

Aedes albopictus (Ae. albopictus) is an important vector of arboviruses such as Dengue virus (DENV), Chikungunya virus (CHIKV), and Zika virus (ZIKV). Long noncoding RNA (lncRNAs) have been identified in other vectors including Aedes aegypti and Anopheles mosquitoes, few of which have been implicated in immunity and viral replication. To identify lncRNAs with potential biological functions in Ae. albopictus, we performed RNA-seq on Ae. albopictus cells infected with DENV and ZIKV, and analyzed them together with public datasets. We identified a total of 23,899 transcripts, 16,089 were intergenic while 3,126 and 4,183 of them were antisense and intronic to annotated genes respectively. Ae. albopictus lncRNAs shared many of the characteristics with their invertebrate and vertebrate counterparts, such as low expression, low GC content, short in length, and low conservation even among closely related species. Compared to protein-coding genes, lncRNAs exhibited higher tendency to be expressed in a stage-specific manner. Besides, expression of lncRNAs and nearest protein-coding genes tended to be correlated, especially for the gene pairs within 1kb from each other. We also discovered that Ae. albopictus lncRNAs have the potential to act as precursors for miRNA and piRNAs, both of which have been implicated in antiviral defense in Aedes mosquito. Upon flavivirus infection, lncRNAs were observed to be differentially expressed, which possibly indicates the involvement of lncRNAs in the host-antiviral defense. Our study provides the first systematic identification of lncRNAs in Ae. albopictus, hence, offering a foundation for future studies of lncRNA functions.

genetics↗

bioRxiv2018

Transcriptome profiles and novel lncRNA identification of Aedes aegypti cells in response to dengue virus serotype 1

Dengue virus (DENV) is a single-stranded, positive-strand RNA virus that belongs to the family of Flaviviridae, and it is mainly transmitted by the mosquito Aedes aegypti (Ae. aegypti). Understanding the interaction of the virus with mosquito vector is vital for devising new strategies for preventing virus transmission. Although protein-coding genes have been the central focus, many reports indicated that long non-coding RNAs (lncRNAs) were also involved in virus-host interaction. Recently, the latest version of Ae. aegypti genome (AaegL5) was released, and the assembly was up to chromosome level. This prompted us to perform lncRNA identification and characterization using the latest genome release as reference. In this study, we investigated the transcriptome profiles of both protein-coding and lncRNA genes in Aedes aegypti cells upon DENV infection. By combining RNA-seq libraries generated in this study with publicly available datasets, we identified a total of 7,221 novel lncRNA transcripts, of which 3,052 and 3,620 were intronic and intergenic respectively, while 549 were antisense to the reference genes. A total of 2,435 differentially expressed transcripts, of which 956 of them were lncRNAs. Overall, the distribution of lncRNA expression and fold change upon virus infection were lower than that of protein-coding genes. We found that the expression of immune-related genes involved in IMD and MAPK signaling pathways were altered. In addition, the expression of major genes involved in RNA-interference (RNAi) pathway that confers antiviral resistance in mosquitoes were found to be unchanged upon DENV infection. Gene ontology analysis suggests that differentially expressed transcripts, either upregulated or downregulated, generally belong to the same functional categories or working in similar signaling pathways. Taken together, besides providing a new set of lncRNA repertoire, the outcomes of our study offer better understanding of Ae. aegypti responses to DENV infection at gene level.\n\nAuthor SummaryDengue virus (DENV), a single-stranded and positive-strand RNA virus of the family Flaviviridae, is primarily transmitted by Aedes aegypti (Ae. aegypti) mosquitoes. There are four closely related but antigenically different serotypes of dengue virus namely DENV1-4. Our understanding on the interaction of each serotype of DENV with its mosquito vector is still very limited. Since vector-borne viruses pose significant burden to public health, knowledge on the virus-host interaction at the molecular level is essential, especially in developing effective strategies to control virus transmission. In this study, we embarked on investigating the transcriptional response of long non-coding RNAs (lncRNAs) and protein-coding genes upon dengue virus serotype 1 (DENV1) infection. Besides, we also generate a comprehensive list of novel lncRNAs identified from the latest and improved genome version of Ae. aegypti. Similar to protein-coding genes, we discovered that the overall expression of lncRNA was significantly altered, suggesting that lncRNAs were involved in virus-host interaction. The results of this study provide basic understanding on the interaction between DENV1 and Ae. aegypti vector at the transcriptional level.

genetics↗