Immunolocalization of cytoplasmic dynein to lysosomes in cultured cells

1992 ◽  
Vol 101 (1) ◽  
pp. 125-137 ◽  
Author(s):  
S.X. Lin ◽  
C.A. Collins

Polyclonal antisera have been raised against cytoplasmic dynein purified from calf brain and rat testis. These antibodies reacted most strongly with the 74 kDa dynein intermediate chain, but also recognized the 410 kDa heavy chain, and the 150 and 45 kDa polypeptides previously observed to copurify with cytoplasmic dynein from rat tissues. Localization studies were performed by indirect immunofluorescence microscopy using a fibroblast cell line. Dynein-specific staining appeared vesicular, distributed throughout the cell, but more concentrated near the nucleus. Double-labeling studies using fluorescent markers for membranous organelles indicated a co-localization of dynein with lysosomes. The distribution of the dynein-positive lysosomes was disrupted by treatment of the cells with microtubule-active drugs, and by acidification of the cytoplasm. Comparison of the distribution of lysosomes with peripheral microtubules indicated a high degree of coincidence. These results are consistent with the hypothesis that cytoplasmic dynein is involved in retrograde-directed movement of membranous organelles. In mitotic cells, dynein staining was also apparent along the microtubules of the mitotic apparatus, though vesicular staining was still conspicuous. The presence of dynein on vesicles as well as on spindle microtubules indicates that dynein distribution between these compartments may be regulated by distinct binding proteins.

1997 ◽  
Vol 138 (5) ◽  
pp. 1055-1066 ◽  
Author(s):  
Tirso Gaglio ◽  
Mary A. Dionne ◽  
Duane A. Compton

The focusing of microtubules into mitotic spindle poles in vertebrate somatic cells has been assumed to be the consequence of their nucleation from centrosomes. Contrary to this simple view, in this article we show that an antibody recognizing the light intermediate chain of cytoplasmic dynein (70.1) disrupts both the focused organization of microtubule minus ends and the localization of the nuclear mitotic apparatus protein at spindle poles when injected into cultured cells during metaphase, despite the presence of centrosomes. Examination of the effects of this dynein-specific antibody both in vitro using a cell-free system for mitotic aster assembly and in vivo after injection into cultured cells reveals that in addition to its direct effect on cytoplasmic dynein this antibody reduces the efficiency with which dynactin associates with microtubules, indicating that the antibody perturbs the cooperative binding of dynein and dynactin to microtubules during spindle/aster assembly. These results indicate that microtubule minus ends are focused into spindle poles in vertebrate somatic cells through a mechanism that involves contributions from both centrosomes and structural and microtubule motor proteins. Furthermore, these findings, together with the recent observation that cytoplasmic dynein is required for the formation and maintenance of acentrosomal spindle poles in extracts prepared from Xenopus eggs (Heald, R., R. Tournebize, T. Blank, R. Sandaltzopoulos, P. Becker, A. Hyman, and E. Karsenti. 1996. Nature (Lond.). 382: 420–425) demonstrate that there is a common mechanism for focusing free microtubule minus ends in both centrosomal and acentrosomal spindles. We discuss these observations in the context of a search-capture-focus model for spindle assembly.


1981 ◽  
Vol 48 (1) ◽  
pp. 241-257
Author(s):  
G.W. Zieve ◽  
J.R. NcIntosh

An anti-serum has been prepared in rabbits that precipitates high-molecular-weight bovine sperm proteins, including the dyneins. The activity of the serum against the dyneins is demonstrated by the recognition of dynein polypeptides in stained electrophoretic profiles of sperm proteins and in immunoprecipitates of radiolabelled sperm proteins. In addition, the serum stains the sperm flagella when used in indirect immunofluorescence and quantitatively inhibits the motility of demembranated sperm reactivated with ATP. However, the serum has additional anti-sperm activities besides those directed against the dyneins as demonstrated by the staining of the acrosome in indirect immunofluorescence. When used to immunoprecipitate proteins from extracts of cultured cells, the serum precipitates 2 polypeptides; one has a molecular weight higher than the flagellar dyneins, one lower. No specific staining of cultured cells is observed when an affinity-purified anti-dynein fraction IgG is used to stain a variety of cultured cells including bovine fibroblasts. We interpret these data to suggest that flagellar dynein is not a component of the mammalian mitotic spindle and discuss how this conclusion is consistent with recent genetic and structural studies on the mitotic spindle.


1996 ◽  
Vol 135 (2) ◽  
pp. 399-414 ◽  
Author(s):  
T Gaglio ◽  
A Saredi ◽  
J B Bingham ◽  
M J Hasbani ◽  
S R Gill ◽  
...  

We use both in vitro and in vivo approaches to examine the roles of Eg5 (kinesin-related protein), cytoplasmic dynein, and dynactin in the organization of the microtubules and the localization of NuMA (Nu-clear protein that associates with the Mitotic Apparatus) at the polar ends of the mammalian mitotic spindle. Perturbation of the function of Eg5 through either immunodepletion from a cell free system for assembly of mitotic asters or antibody microinjection into cultured cells leads to organized astral microtubule arrays with expanded polar regions in which the minus ends of the microtubules emanate from a ring-like structure that contains NuMA. Conversely, perturbation of the function of cytoplasmic dynein or dynactin through either specific immunodepletition from the cell free system or expression of a dominant negative subunit of dynactin in cultured cells results in the complete lack of organization of microtubules and the failure to efficiently concentrate the NuMA protein despite its association with the microtubules. Simultaneous immunodepletion of these proteins from the cell free system for mitotic aster assembly indicates that the plus end-directed activity of Eg5 antagonizes the minus end-directed activity of cytoplasmic dynein and a minus end-directed activity associated with NuMA during the organization of the microtubules into a morphologic pole. Taken together, these results demonstrate that the unique organization of the minus ends of microtubules and the localization of NuMA at the polar ends of the mammalian mitotic spindle can be accomplished in a centrosome-independent manner by the opposing activities of plus end- and minus end-directed motors.


2019 ◽  
Author(s):  
Mark Workentin ◽  
François Lagugné-Labarthet ◽  
Sidney Legge

In this work we present a clean one-step process for modifying headgroups of self-assembled monolayers (SAMs) on gold using photo-enabled click chemistry. A thiolated, cyclopropenone-caged strained alkyne precursor was first functionalized onto a flat gold substrate through self-assembly. Exposure of the cyclopropenone SAM to UV-A light initiated the efficient photochemical decarbonylation of the cyclopropenone moiety, revealing the strained alkyne capable of undergoing the interfacial strain-promoted alkyne-azide cycloaddition (SPAAC). Irradiated SAMs were derivatized with a series of model azides with varied hydrophobicity to demonstrate the generality of this chemical system for the modification and fine-tuning of the surface chemistry on gold substrates. SAMs were characterized at each step with polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) to confirm successful functionalization and reactivity. Furthermore, to showcase the compatibility of this approach with biochemical applications, cyclopropenone SAMs were irradiated and modified with azide-bearing cell adhesion peptides to promote human fibroblast cell adhesion, then imaged by live cell fluorescence microscopy. Thus, the “photoclick” methodology reported here represents an improved, versatile, catalyst-free protocol that allows for a high degree of control over the modification of material surfaces, with applicability in materials science as well as biochemistry.<br>


2005 ◽  
Vol 16 (7) ◽  
pp. 3107-3116 ◽  
Author(s):  
Anindya Ghosh-Roy ◽  
Bela S. Desai ◽  
Krishanu Ray

Toward the end of spermiogenesis, spermatid nuclei are compacted and the clonally related spermatids individualize to become mature and active sperm. Studies in Drosophila showed that caudal end-directed movement of a microfilament-rich structure, called investment cone, expels the cytoplasmic contents of individual spermatids. F-actin dynamics plays an important role in this process. Here we report that the dynein light chain 1 (DLC1) of Drosophila is involved in two separate cellular processes during sperm individualization. It is enriched around spermatid nuclei during postelongation stages and plays an important role in the dynein-dynactin–dependent rostral retention of the nuclei during this period. In addition, DDLC1 colocalizes with dynamin along investment cones and regulates F-actin assembly at this organelle by retaining dynamin along the cones. Interestingly, we found that this process does not require the other subunits of cytoplasmic dynein-dynactin complex. Altogether, these observations suggest that DLC1 could independently regulate multiple cellular functions and established a novel role of this protein in F-actin assembly in Drosophila.


1998 ◽  
Vol 46 (10) ◽  
pp. 1203-1209 ◽  
Author(s):  
Françoise Jaunin ◽  
Astrid E. Visser ◽  
Dusan Cmarko ◽  
Jacob A. Aten ◽  
Stanislav Fakan

We describe a colloidal gold immunolabeling technique for electron microscopy which allows one to differentially visualize portions of DNA replicated during different periods of S-phase. This was performed by incorporating two halogenated deoxyuridines (IdUrd and CldUrd) into Chinese hamster cells and, after cell processing, by detecting them with selected antibodies. This technique, using in particular appropriate blocking solutions and also Tris buffer with a high salt concentration and 1% Tween-20, prevents nonspecific background and crossreaction of both antibodies. Controls such as digestion with DNase and specific staining of DNA with osmium ammine show that labeling corresponds well to replicated DNA. Different patterns of labeling distribution, reflecting different periods of DNA replication during S-phase, were characterized. Cells in early S-phase display a diffuse pattern of labeling with many spots, whereas cells in late S-phase show labeling confined to larger domains, often at the periphery of the nucleus or associated with the nucleolus. The good correlation between our observations and previous double labeling results in immunofluorescence also proved the technique to be reliable.


1993 ◽  
Vol 41 (4) ◽  
pp. 627-630 ◽  
Author(s):  
S Würden ◽  
U Homberg

We have developed a new double immunofluorescence technique by which two neuroactive substances in the same tissue section can be labeled with primary antisera raised in the same species. The optic lobes of the locust Schistocerca gregaria were used as a model system to develop the staining procedure. FMRFamide-immunoreactive neurons were detected by rabbit antisera against FMRFamide and FITC-conjugated secondary antibodies. Antibodies against the second peptide, pigment-dispersing hormone (PDH), also raised in rabbit, were biotinylated and detected via streptavidin-Texas Red. Crossreactivity of the PDH immunoglobulins with the FITC-conjugated secondary antiserum was prevented by pre-incubation with rabbit gamma globulins. The two peptide immunoreactivities could be conveniently observed on the same section with the different fluorescent markers. This double labeling technique with modified antibodies is easily performed and highly useful for co-localization studies with antisera raised in the same species.


2020 ◽  
Author(s):  
Tao Wang ◽  
Zelong Li ◽  
Jinpu Wei ◽  
Dongmin Zheng ◽  
Chen Wang ◽  
...  

AbstractThe population decline in the common hippopotamus (Hippopotamus amphibius) has necessitated the preservation of their genetic resources for species conservation and research. Of all actions, cryopreservation of fibroblast cell cultures derived from animal biopsy is considered a simple but efficient means. Nevertheless, preserving viable cell cultures of the common hippopotamus has not been achieved to our knowledge. To this end, we detailed a method to establish fibroblast cell cultures from a female common hippopotamus fetus in this study. By combining the classic tissue explant direct culture and enzymatic digestion methods, we isolated a great number of cells with typical fibroblastic morphology and high viability. Characterization of the fibroblast cultures was carried out using different techniques. In short, neither bacteria/fungi nor mycoplasma was detectable in the cell cultures throughout the study. The population doubling time was 23.9 h according to the growth curve. Karyotyping based on Giemsa staining showed that cultured cells were diploid with 36 chromosomes in all, one pair of which was sex chromosomes. Mitochondrial cytochrome C oxidase subunit I gene sequence of the cultured cells was 99.26% identical with the Hippopotamus amphibius complete mitochondrial DNA sequence registered in GenBank, confirming the cells were derived from a common hippopotamus. Flow cytometry and immunofluorescence staining results revealed that the detected cells were positive for fibroblast markers, S100A4 and Vimentin. In conclusion, we isolated and characterized a new fibroblast cell culture from a common hippopotamus skin sample and the cryopreserved cells could be useful genetic materials for the future research.


2017 ◽  
Author(s):  
Fabio Zanini ◽  
Szu-Yuan Pu ◽  
Elena Bekerman ◽  
Shirit Einav ◽  
Stephen R. Quake

ABSTRACTDengue and Zika viral infections affect millions of people annually and can be complicated by hemorrhage or neurological manifestations, respectively. However, a thorough understanding of the host response to these viruses is lacking, partly because conventional approaches ignore heterogeneity in virus abundance across cells. We present viscRNA-Seq (virus-inclusive single cell RNA-Seq), an approach to probe the host transcriptome together with intracellular viral RNA at the single cell level. We applied viscRNA-Seq to monitor dengue and Zika virus infection in cultured cells and discovered extreme heterogeneity in virus abundance. We exploited this variation to identify host factors that show complex dynamics and a high degree of specificity for either virus, including proteins involved in the endoplasmic reticulum translocon, signal peptide processing, and membrane trafficking. We validated the viscRNA-Seq hits and discovered novel proviral and antiviral factors. viscRNA-Seq is a powerful approach to assess the genome-wide virus-host dynamics at single cell level.


1993 ◽  
Vol 105 (2) ◽  
pp. 579-588 ◽  
Author(s):  
S.X. Lin ◽  
C.A. Collins

Previous work has indicated that cytoplasmic dynein localizes primarily to lysosomes in cultured fibroblasts, consistent with a function for dynein in retrograde movement. We now show that dynein can be redistributed from a lysosome-associated pool to a more diffuse cytoplasmic pool upon shifting fibroblasts to culture medium lacking serum for several hours. This effect on dynein localization is readily reversed upon addition of serum, with a substantial return to a control appearance of punctate staining within 10 minutes. The serum effect appears to be selective for dynein, in that the localization of kinesin and the overall morphology of intracellular organelles does not change. However, the distribution of kinesin-positive vesicles and lysosomes does appear to be altered during serum starvation, in that these organelles are located to greater extents in the peripheral regions of the cell. Dynein is also associated with the mitotic apparatus, but this localization does not change in response to serum starvation. Removal of calcium from the extracellular medium also results in the loss of punctate dynein staining, which can be recovered upon addition of calcium to calcium-free medium. The redistribution of dynein observed under these experimental conditions may reflect the activity of a regulatory process controlling the association of dynein with organelles, thereby providing one means of modulating intracellular transport.


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