scholarly journals Arf6, JIP3, and dynein shape and mediate macropinocytosis

2019 ◽  
Vol 30 (12) ◽  
pp. 1477-1489 ◽  
Author(s):  
Chad D. Williamson ◽  
Julie G. Donaldson
Keyword(s):  
Cell Line ◽  
Myosin Ii ◽  
Signaling Molecules ◽  
Scaffold Protein ◽  
Interacting Protein ◽  
Fibrosarcoma Cell ◽  
Ht1080 Cells ◽  
Lamellar Region ◽  
Microtubule Motor

Macropinocytosis is an actin-driven form of clathrin-independent endocytosis that generates an enlarged structure, the macropinosome. Although many studies focus on signaling molecules and phosphoinositides involved in initiating macropinocytosis, the commitment to forming a macropinosome and the handling of that membrane have not been studied in detail. Here we show in HT1080 cells, a human fibrosarcoma cell line, a requirement for microtubules, dynein, the JIP3 microtubule motor scaffold protein, and Arf6, a JIP3 interacting protein, for the formation and inward movement of the macropinosome. While actin and myosin II also play critical roles in the formation of ruffling membrane, microtubules provide an important tract for initiation, sealing, and transport of the macropinosome through the actin- and myosin-rich lamellar region.

scholarly journals Generation of High-Yield, Functional Oligodendrocytes from a c-myc Immortalized Neural Cell Line, Endowed with Staminal Properties

2021 ◽  
Vol 22 (3) ◽  
pp. 1124
Author(s):  
Mafalda Giovanna Reccia ◽  
Floriana Volpicelli ◽  
Eirkiur Benedikz ◽  
Åsa Fex Svenningsen ◽  
Luca Colucci-D’Amato
Keyword(s):  
Cell Line ◽  
Low Cost ◽  
Neural Cell ◽  
New Drugs ◽  
High Yield ◽  
Time Saving ◽  
Interacting Protein ◽  
Neuronal Marker ◽  
Differentiation Status

Neural stem cells represent a powerful tool to study molecules involved in pathophysiology of Nervous System and to discover new drugs. Although they can be cultured and expanded in vitro as a primary culture, their use is hampered by their heterogeneity and by the cost and time needed for their preparation. Here we report that mes-c-myc A1 cells (A1), a neural cell line, is endowed with staminal properties. Undifferentiated/proliferating and differentiated/non-proliferating A1 cells are able to generate neurospheres (Ns) in which gene expression parallels the original differentiation status. In fact, Ns derived from undifferentiated A1 cells express higher levels of Nestin, Kruppel-like factor 4 (Klf4) and glial fibrillary protein (GFAP), markers of stemness, while those obtained from differentiated A1 cells show higher levels of the neuronal marker beta III tubulin. Interestingly, Ns differentiation, by Epidermal Growth Factors (EGF) and Fibroblast Growth Factor 2 (bFGF) withdrawal, generates oligodendrocytes at high-yield as shown by the expression of markers, Galactosylceramidase (Gal-C) Neuron-Glial antigen 2 (NG2), Receptor-Interacting Protein (RIP) and Myelin Basic Protein (MBP). Finally, upon co-culture, Ns-A1-derived oligodendrocytes cause a redistribution of contactin-associated protein (Caspr/paranodin) protein on neuronal cells, as primary oligodendrocytes cultures, suggesting that they are able to form compact myelin. Thus, Ns-A1-derived oligodendrocytes may represent a time-saving and low-cost tool to study the pathophysiology of oligodendrocytes and to test new drugs.

scholarly journals Selective expression of the scaffold protein JSAP1 in spermatogonia and spermatocytes

Reproduction ◽  
2006 ◽  
Vol 131 (4) ◽  
pp. 711-719 ◽  
Author(s):  
Munkhuu Bayarsaikhan ◽  
Akiko Shiratsuchi ◽  
Davaakhuu Gantulga ◽  
Yoshinobu Nakanishi ◽  
Katsuji Yoshioka
Keyword(s):  
Protein Kinase ◽  
Western Blotting ◽  
Cell Types ◽  
Mapk Signaling ◽  
Scaffold Protein ◽  
Mitogen Activated Protein Kinase ◽  
Interacting Protein ◽  
Early Postnatal Development ◽  
Mitogen Activated Protein ◽  
Signaling Modules

Scaffold proteins of mitogen-activated protein kinase (MAPK) intracellular signal transduction pathways mediate the efficient and specific activation of the relevant MAPK signaling modules. Previously, our group and others have identified c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase-associated protein 1 (JSAP1, also known as JNK-interacting protein 3) as a scaffold protein for JNK MAPK pathways. Although JSAP1 is expressed in the testis in adults, its expression during development has not been investigated. In addition, it is unknown which types of cells in the testis express the scaffold protein. Here, we examined the expression of JSAP1 in the testis of mice aged 14 days, 20 days, 6 weeks, and 12 weeks by immunohistochemistry and Western blotting. The specificity of the anti-JSAP1 antibody was evaluated from its reactivity to exogenously expressed JSAP1 and a structurally related protein, and by antigen-absorption experiments. The immunohistochemical analyses with the specific antibody showed that the JSAP1 protein was selectively expressed in the spermatogonia and spermatocytes, but not in other cell types, including spermatids and somatic cells, during development. However, not all spermatogonia and spermatocytes were immunopositive either, especially in the 12-week-old mouse testis. Furthermore, we found by Western blotting that the expression levels of JSAP1 protein vary during development; there is high expression until 6 weeks after birth, which approximately corresponds to the end of the first wave of spermatogenesis. Collectively, these results suggest that JSAP1 function may be important in spermatogenic cells during early postnatal development.

Abstract 1500: A novel nutrient mixture exhibits antitumor activity in human fibrosarcoma cell line HT-1080

2011 ◽  
Author(s):  
M. Waheed Roomi ◽  
Neil Jariwalla ◽  
Nusrath Roomi ◽  
Matthias Rath ◽  
Aleksandra Niedzwiecki
Keyword(s):  
Antitumor Activity ◽  
Cell Line ◽  
Fibrosarcoma Cell

scholarly journals SHP-1 Phosphatase C-Terminus Interacts With Novel Substrates p32/p30 During Erythropoietin and Interleukin-3 Mitogenic Responses

Blood ◽  
1998 ◽  
Vol 91 (10) ◽  
pp. 3746-3755 ◽  
Author(s):  
Wentian Yang ◽  
Mina Tabrizi ◽  
Karim Berrada ◽  
Taolin Yi
Keyword(s):  
Cell Line ◽  
Hematopoietic Cells ◽  
Signaling Molecules ◽  
Erythropoietin Receptor ◽  
Negative Regulator ◽  
Growth Responses ◽  
Mitogenic Signaling ◽  
Hematopoietic Growth Factors ◽  
Interleukin 3 ◽  
C Terminus

Abstract SHP-1 protein tyrosine phosphatase is a critical negative regulator of mitogenic signaling, as demonstrated by the heightened growth responses to hematopoietic growth factors in hematopoietic cells of motheaten mice, which lack functional SHP-1 expression due to mutations in the SHP-1 gene. The mitogenic signaling molecules dephosphorylated by SHP-1 have not been fully identified. We detected two proteins (p32/p30) that are hyperphosphorylated in a DA3/erythropoietin receptor (EpoR) cell line that expresses a mutant containing the SHP-1 C-terminus that suppresses the function of the endogenous phosphatase and induces hyperproliferative responses to interleukin-3 (IL-3) and Epo. Hyperphosphorylated p32/p30 are also detected in motheaten hematopoietic cells, demonstrating an association of p32/p30 hyperphosphorylation with SHP-1-deficiency and growth factor-hyperresponsiveness. The hyperphosphorylated p32/30 associate with SHP-1 via its C-terminus, because they coimmunoprecipitate with the phosphatase and the C-terminal mutant and they bind in vitro to a synthetic peptide of the mutant but not the GST fusion proteins of SHP-1 SH2 domains. Induction of p32/p30 phosphorylation by IL-3 or Epo occurs mainly at 2 to 18 hours poststimulation in the DA3/EpoR cell line, indicating p32/p30 as novel signaling molecules during cell cycle progression. These data demonstrate a function for the SHP-1 C-terminus in recruiting potential substrates p32/p30 and suggest that SHP-1 may regulates mitogenic signaling by dephosphorylating p32/p30.

scholarly journals A Specific Isoform of Nonmuscle Myosin II-C Is Required for Cytokinesis in a Tumor Cell Line

2006 ◽  
Vol 281 (34) ◽  
pp. 24662-24670 ◽  
Author(s):  
Siddhartha S. Jana ◽  
Sachiyo Kawamoto ◽  
Robert S. Adelstein
Keyword(s):  
Tumor Cell ◽  
Cell Line ◽  
Myosin Ii ◽  
Tumor Cell Line ◽  
Nonmuscle Myosin ◽  
Nonmuscle Myosin Ii

HETEROGENOUS EXPRESSION OF PLASMINOGEN ACTIVATOR (PA) GENES IN THE HUMAN SARCOMA CELL LINE HT1080

1987 ◽  
Author(s):  
Walter E Laug
Keyword(s):  
Gene Expression ◽  
Tumor Cell ◽  
Cell Line ◽  
Tumor Cell Line ◽  
Tissue Type ◽  
Gene Probe ◽  
Ht1080 Cell ◽  
Simultaneous Production ◽  
Tissue Invasion ◽  
Ht1080 Cells

Tumor cell derived PA activities are of crucial importance for tissue invasion and destruction by tumor cells. Therefore, we studied the expression of the PA genes in HT1080 cells using immunoenzymatic methods and specific PA gene probes.Immunenzymatic methods allowed only for the detection of urokinase like PA (u-PA) activities in HT1080 cells which was suppressed by treatment of the cells with dexamethasone (10-7 m). Despite the lack of u-PA activities, the cells still degraded extracellular tissue glycoproteins. Northern blot analysis with specific PA gene probe showed that HT1080 cells express both tissue type PA (t-PA) and u-PA. The enzymatic activities of t-PA were most likely masked by the simultaneous production of inhibitors of PA (PAI). Treatment of HT1080 cells with dexamethasone resulted in increased transcription of t-PA and decreased expression of the u-PA gene, explaining the unchanged tissue destruction by dexamethasone treated HT1080 cells.Cell clones secreting either large or small amounts of enzymatic PA activities were isolated from the parental HT1080 cell line using a fibrin agarose overlay technique.The expression of the u-PA gene was enhanced in high secreting PA clones compared to low secreting PA clones when analyzed on Northern blots. This heterogenous expression of the u-PA gene within the HT1080 cell line was confirmed by in situ hybridization with a specific u-PA gene probe.These findings demonstrate that PA gene expression can be missed with immunenzymatic methods due to simultaneous production of inhibitors of PA. In addition our results show that the expression of a given PA gene may be heterogenous on the cellular level within an established tumor cell line. These findings, therefore, suggest cellular variation of PA gene expression in tumor which may be of fundamental importance for tissue invasion and metastasis by cancer cells.

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