Stage-specific localization of the small heat shock protein Hsp27 during oogenesis inDrosophila melanogaster (original) (raw)
Related papers
Journal of cell science, 1997
The developmental and heat-shock-induced expression of two small heat-shock proteins (Hsp23 and Hsp27) was investigated during spermatogenesis in Drosophila melanogaster. Both of these Hsps were expressed in unstressed and stressed male gonads as shown by immunoblotting. Immunostaining of whole-mount organs and thin sections of testes showed that an anti-Hsp23 antibody specifically decorated cells of the somatic lineage, such as the cyst cells and the epithelial cells of the testis and of the seminal vesicle. Hsp27 was expressed in some somatic cells (cyst cells and epithelial cells of the accessory glands) and, in addition, was also visible in the maturing spermatocytes of the germline. The same cell-specific pattern of expression was observed after heat shock, and cells which did not express Hsp23 and Hsp27 in the absence of stress were similarly unable to mount a heat shock response for these s-Hsps. However other Hsps such as Hsp70 and Hsp22 were induced under heat-shock conditi...
Regulation of heat shock gene induction and expression during Drosophila development
Cellular and Molecular Life Sciences, 1997
Some heat shock genes are expressed in the absence of stress during embryogenesis and metamorphosis in the fruit fly Drosophila melanogaster. Their functions in these processes are unknown. During development, each of the four members of the small heat shock protein family (Hsp27, Hsp26, Hsp23 and Hsp22), which are coordinately induced in response to a heat stress, shows a specific pattern of expression in diverse tissues and cells. This expression is driven through cell-specific enhancers in the promoter regions of their genes. In addition, some of the Hsps show cell-specific induction by heat shock. Hsp23, for example, is only inducible in a single cell type (cone cells) of the eye ommatidium, while the other small Hsps are inducible in all cells of the eye unit. In germ line tissues such as testes, Hsp23 and 27 are both readily expressed in the absence of stress (albeit in distinct cell lineages) and cannot be further induced by heat shock. Hsp27 is expressed throughout oogenesis, but its intracellular localization is stage-specific, being nuclear from germarium to stage 6 and cytoplasmic from stage 8 onwards. Finally the small Hsps show tissue-specific post-translational modifications. Thus the function(s) of the small Hsps may be modulated by different cell and developmental stage-specific mechanisms operating either on their expression, their cellular localization or their structure by post-translational modifications.
Genome
The cellular distribution and expression of hsp-23 in Drosophila Kc cultured cells was studied by indirect immunofluorescence. In unstressed cells, hsp-23 is only expressed in less than 5% of the cellular population and shows an exclusive cytoplasmic localization. Following heat shock, the 23-kilodalton (kDa) heat-shock protein (HSP) is present in all cells; it can be found both in the nucleolus and in granules in the cytoplasm. After 3 h of recovery at 23"C, the 23-kDa HSP returns to the cytoplasm where it shows a diffuse distribution. Thus the previously reported low amounts of the 23-kDa HSP in unstressed cells does not seem to represent a basal level of expression in every cell but rather selective expression in certain cells.
Biochemical and Immunocytochemical Localization of Heat-Shock Proteins in Drosophila Cultured Cells
Annals of the New York Academy of Sciences, 1985
Treatment of living cells at supraoptimal temperatures or with various chemical or physical aggressors induces the synthesis of a group of proteins known as heat-shock proteins (HSP).'.2 The function of these ubiquitous proteins is unclear although a role in cellular protection has been ~uggested.~ In Drosophila cultured cells, biochemical fractionation of HS cells shows an enrichment of most HSPs (with the exception of HSP 82) in the nuclear pellet following HS.4,' In the course of studies on the characterization of a major intermediate filament-like cytoskeletal protein of 46,000 in these we observed that the group of low molecular weight HSPs tended to copurify with a Triton-high salt insoluble' cytoskeletal fraction (FIGURE 1). In order to investigate the significance of this finding and to elucidate the function of HSPs, we prepared polyclonal antibodies against HSP 82, 70, 68, and 23 and studied their intracellular distribution by immunofluorescence techniques following heat shock and during recovery. The antibodies were purified by affinity and their specificity checked by immunoblotting. The results are summarized in FIGURE 2.
Hsp60C is required in follicle as well as germline cells during oogenesis inDrosophila melanogaster
Developmental Dynamics, 2008
Hsp60C gene of Drosophila melanogaster shows a dynamic spatiotemporal expression during oogenesis and seems to contribute bulk of the Hsp60 family proteins in ovarioles. Hsp60 distribution overlaps with that of F-actin–rich membranes/structures in follicle, nurse, and egg cells throughout oogenesis. Skeletal muscle fibers associated with ovarioles and in other parts of the body show patterned location of Hsp60 in A-bands. During stages 11–12, Hsp60 accumulates at junctions of nurse cells and oocyte, where a new microtubule organizing center is known to develop. A recessive hypomorph allele, Hsp60C1 causes complete sterility of the rare surviving homozygous adults. Their egg chambers show very little Hsp60C transcripts or Hsp60 protein. Beginning at stages 6–7, Hsp60C1 chambers show a disorganized follicle cell layer with poor cell adhesion in addition to abnormal organization of F-actin and other cytoskeletal structures in follicle, nurse, and egg cells. Additionally, expression and localizations of Hrb98DE, Squid, and Gurken proteins in nurse cells and oocyte are also severely affected. Hsp60C1 homozygous follicle cell clones in Hsp60C1/+ ovarioles show disruptions in follicle epithelial and cytoskeleton arrangements. Likewise, egg chambers with Hsp60C1 homozygous germline clones in Hsp60C1/+ flies show abnormal oogenesis. Our results provide the first evidence for an essential role of Hsp60C in Drosophila oogenesis, especially in organization and maintenance of cytoskeletal and cell adhesion components. Developmental Dynamics 237:1334-1347, 2008. © 2008 Wiley-Liss, Inc.
Genetics and Molecular Biology, 2007
The expression pattern of two major chaperones, the heat shock proteins (HSPs) HSP60 and HSP70 was studied in vitro in tissues of the housefly Musca domestica during larval and adult stages of development to identify their immunological relatives and understand their functional significance in normal cellular activities and during thermal stress. Fluorographs of labeled polypeptides and western blots demonstrated that both HSPs are expressed constitutively and heat-induced in all the larval and adult cell types examined. The pattern of whole tissue immunocytochemical staining using anti-HSP60 and anti-HSP70 antibodies corresponded well with the observations from western blots or fluorographs. In developing oocytes, both constitutive and heat inducible expression of HSP60 were regulated in an oocyte stage-specific manner. In unstressed ovaries the expression of these proteins was less pronounced in early stage oocytes (1 st-8 th) than at later stages (9 th and onward). The heat shock, however, induced both HSP70 and HSP60 to a significantly high level in early stage oocytes (1 st-8 th) as compared to their respective controls. Our findings indicate the involvement of the HSP60 and HSP70 proteins in the development, growth and differentiation of both somatic and germ line tissues. Furthermore, the enhanced co-expression of HSP70 and HSP60 upon heat shock in various larval and adult cell types suggests the possible role of HSP60 in thermoprotection.
Small Heat Shock Protein and Drosophila melanogaster Development
Advances in Zoology and Botany, 2023
To understand the regulation and function of the heat shock response, Drosophila model system has been used for the past few decades. Drosophila heat shock protein is a family of proteins which show large changes in their expression pattern upon deviation from optimal temperature of organism in either direction, thereby preventing cells from potential damages. Small heat shock protein (sHsp) is a subfamily under this family and is known for its role in a wide variety of cellular functions (ageing, immunity, proteotoxicity, apoptosis, etc.) apart from maintaining homeostasis. In all domains of drosophila life cycle, ATP-independent stress proteins i.e. small heat shock proteins (sHsps) are found. The review highlights the various roles played by different members of sHsp in Drosophila melanogaster and their contribution to ageing and autophagy. Some members of the subfamily also show differential localization in different organelles and tissues, at different developmental stages as well as in adults owing to their functions. For understanding protein function, determination and localization of cellular proteins was studied. Determining the cellular localization of proteins is important for understanding protein functions. Some of the Hsps are up-regulated in organ and tissue-specific manner which help to understand life span and different biomarkers during the course of Drosophila life cycle. Some of the members of small heat shock protein in Drosophila melanogaster are orthologs of human sHsp and hence can serve as a good model for studying diseases in humans associated with members of this subfamily. Different parameters and tools can be used experimentally which will help in manipulating gene function and determining health span in Drosophila. This provides an unparalleled opportunity to further study the role of sHsps. Keywords Drosophila melanogaster, Small Heat Shock Proteins, Proteotoxicity, Aging, Homeostasis
Heat shock response in ovarian nurse cells ofAnopheles stephensi
Journal of Biosciences, 1989
Transcriptional and translational changes following temperature shock at 37, 39 or 41°C to ovarian cells of Anopheles stephensi were studied. Temperature shock at 39°C induced 6 puffs on polytene chromosomes in the nurse cells as revealed by [ 3 H] uridine incorporation studies. Only the 2R-19B puff was induced at 37°C and was found to be a major temperature shock locus remaining most active at all the 3 temperatures tested. Other temperature shock loci were activated only at 39°C. There was progressive inhibi tion of general chromosomal transcription with the rise of temperature. Transcription was drastically inhibited at 41°C but all the temperature shock loci still remained relatively active. Examination of [ 35 S]methionine labelled newly synthesized ovarian proteins using sodium dodecyl sulphate-polyacrylamide slab gels revealed that all the heat shock polypeptides except the HSP 70 were synthesized in ovarian cells even at control temperature (29°C). Temperature shock induced the synthesis of HSP 70 and elevated the levels of other heat shock polypeptides (82, 30, 29, 23 and 17 KD). Present results suggest that the threshold level for induction of a complete heat shock response in mosquitos is higher (39°C) than the other dipteran insects studied and that a 41°C treatment is not lethal as in the case of Drosophila, Chironomus etc. These features reflect the adaptations of mosquitos to tropical climate and their dietary habit of warm blood meal.