Discriminating gene expression profiles of memory B cell subpopulations

Morphologically and functionally distinct subpopulations of human memory B (BMem) cells are identifiable by either their expression of CD27 or Fc receptor–like 4 (FCRL4), an immunoglobulin domain containing a receptor with strong inhibitory potential. We have conducted comparative transcriptome and proteome analyses of FCRL4+ and FCRL4− BMem cells and found that these two subsets have very distinctive expression profiles for genes encoding transcription factors, cell-surface proteins, intracellular signaling molecules, and modifiers of the cell-cycle status. Among the differentially expressed transcription factors, runt-related transcription factor 1 (RUNX1) transcript levels were up-regulated in FCRL4− cells, whereas RUNX2 transcripts were preferentially detected in FCRL4+ cells. In vitro evidence for FCRL4 promoter responsiveness and in vivo promoter occupancy suggested that RUNX transcription factors are involved in the generation of these BMem cell subpopulations. A distinctive signature profile was defined for the FCRL4+ BMem cells by their expression of CD11c, receptor activator for nuclear factor κB ligand, and FAS cell-surface proteins, in combination with increased levels of SOX5, RUNX2, DLL1, and AICDA expression. We conclude that this recently identified subpopulation of BMem cells, which normally resides in epithelial tissue-based niches, may serve a unique role in mucosal defense and, conversely, as a target for neoplastic transformation events.

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In Vitro and In Vivo Biotinylation of Endothelial Cell Surface Proteins in the Pursuit of Targets for Vascular Therapies for Brain AVMs

Journal of Postgenomics Drug & Biomarker Development ◽

10.4172/2153-0769.s1-007 ◽

2012 ◽

Vol 01 (S1) ◽

Cited By ~ 5

Author(s):

Margaret Simonian ◽

Mark P Molloy

Keyword(s):

Endothelial Cell ◽

Cell Surface ◽

Surface Proteins ◽

Cell Surface Proteins ◽

Endothelial Cell Surface ◽

Brain Avms

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Membrane protein redistribution during differentiation of cultured human erythroleukemic cells.

Molecular and Cellular Biology ◽

10.1128/mcb.1.12.1150 ◽

1981 ◽

Vol 1 (12) ◽

pp. 1150-1162 ◽

Cited By ~ 8

Author(s):

R C Hunt ◽

L M Marshall

Keyword(s):

Cell Surface ◽

K562 Cells ◽

Erythroid Differentiation ◽

Surface Proteins ◽

Cell Surface Proteins ◽

Mature Erythrocyte ◽

Transmission Electron ◽

Immune Precipitation

Human erythroleukemic (K562) cells differentiate along the erythroid differentiation pathway in vitro when 0.05 mM hemin is included in the growth medium. In the presence of the inducer the cells continue to proliferate and, after a delay of 24 to 48 h, start to synthesize hemoglobin. However, during differentiation, no changes in the major cell surface proteins were detected using lactoperoxidase-catalyzed iodination, and no change in the synthesis of spectrin, the major cytoskeletal protein of the mature erythrocyte, was detected by specific immune precipitation. Despite this absence of major changes in cell surface proteins, profound changes take place in the organization of the cell membranes. A process similar but not identical to the enucleation observed in erythroid differentiation in vivo occurs in which a smooth-surfaced cell, about 10 micrometers in diameter, is divided from the nucleus-containing part of the cell. With the exception of ribosomes, these reticulocyte-like cells contain no organelles when examined by transmission electron microscopy, but contain much of the parent cell's hemoglobin, spectrin, and glycophorin.

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Membrane protein redistribution during differentiation of cultured human erythroleukemic cells

Molecular and Cellular Biology ◽

10.1128/mcb.1.12.1150-1162.1981 ◽

1981 ◽

Vol 1 (12) ◽

pp. 1150-1162

Author(s):

R C Hunt ◽

L M Marshall

Keyword(s):

Cell Surface ◽

K562 Cells ◽

Erythroid Differentiation ◽

Surface Proteins ◽

Cell Surface Proteins ◽

Mature Erythrocyte ◽

Transmission Electron ◽

Immune Precipitation

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Cell Surface Expression of Nrg1 Protein in Candida auris

Journal of Fungi ◽

10.3390/jof7040262 ◽

2021 ◽

Vol 7 (4) ◽

pp. 262

Author(s):

Anuja Paudyal ◽

Govindsamy Vediyappan

Keyword(s):

Cell Surface ◽

Growth Conditions ◽

Zinc Ion ◽

Surface Proteins ◽

Cell Surface Expression ◽

Unexpected Finding ◽

Candida Auris ◽

Cell Surface Proteins ◽

Biofilm Growth

Candida auris is an emerging antifungal resistant human fungal pathogen increasingly reported in healthcare facilities. It persists in hospital environments, and on skin surfaces, and can form biofilms readily. Here, we investigated the cell surface proteins from C. auris biofilms grown in a synthetic sweat medium mimicking human skin conditions. Cell surface proteins from both biofilm and planktonic control cells were extracted with a buffer containing β-mercaptoethanol and resolved by 2-D gel electrophoresis. Some of the differentially expressed proteins were excised and identified by mass spectrometry. C. albicans orthologs Spe3p, Tdh3p, Sod2p, Ywp1p, and Mdh1p were overexpressed in biofilm cells when compared to the planktonic cells of C. auris. Interestingly, several proteins with zinc ion binding activity were detected. Nrg1p is a zinc-binding transcription factor that negatively regulates hyphal growth in C. albicans. C. auris does not produce true hypha under standard in vitro growth conditions, and the role of Nrg1p in C. auris is currently unknown. Western blot analyses of cell surface and cytosolic proteins of C. auris against anti-CalNrg1 antibody revealed the Nrg1p in both locations. Cell surface localization of Nrg1p in C. auris, an unexpected finding, was further confirmed by immunofluorescence microscopy. Nrg1p expression is uniform across all four clades of C. auris and is dependent on growth conditions. Taken together, the data indicate that C. auris produces several unique proteins during its biofilm growth, which may assist in the skin-colonizing lifestyle of the fungus during its pathogenesis.

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Laminin E8 alveolarization site: heparin sensitivity, cell surface receptors, and role in cell spreading

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1997.272.3.l494 ◽

1997 ◽

Vol 272 (3) ◽

pp. L494-L503

Author(s):

L. Chen ◽

V. Shick ◽

M. L. Matter ◽

S. M. Laurie ◽

R. C. Ogle ◽

...

Keyword(s):

Cell Adhesion ◽

Cell Surface ◽

Surface Proteins ◽

Cell Surface Proteins ◽

Surface Receptors ◽

Beta1 Integrin ◽

Alpha Dystroglycan ◽

Alveolar Formation ◽

Laminin 1

Cell adhesion to amino acids 2179-2198 (SN-peptide) of the laminin-1 alpha1-chain is required for lung alveolar formation in vitro (M. L. Matter and G. W. Laurie. J. Cell Biol. 124: 1083-1090, 1994). The nature of the SN-peptide receptor(s) was probed with neutralizing anti-integrin monoclonal antibodies (MAb), cells lacking integrin subunits, soluble heparin, and SN-peptide columns. Cell adhesion and spreading studies confirmed the specificity of SN-peptide and revealed adhesion to be unaffected by inclusion of anti-beta1-, anti-alpha(2-6)- or anti-alpha(V)beta5-integrin MAb. Cells lacking beta1- or alpha6-integrin subunits were fully adherent. Adhesion was heparin, but not chondroitin sulfate or heparinase, sensitive, much as is alpha-dystroglycan-laminin-1 binding. Heparin eluted approximately 155- and 180-kDa cell-surface proteins from SN-peptide columns. An additional approximately 91-kDa protein was eluted by EDTA. All were unrecognized by anti-beta1-integrin MAb. SN-peptide therefore interacts with three cell-surface proteins for which the identity remains to be determined.

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c-Jun Homodimers Can Function as a Context-Specific Coactivator

Molecular and Cellular Biology ◽

10.1128/mcb.00936-06 ◽

2007 ◽

Vol 27 (8) ◽

pp. 2919-2933 ◽

Cited By ~ 33

Author(s):

Benoit Grondin ◽

Martin Lefrancois ◽

Mathieu Tremblay ◽

Marianne Saint-Denis ◽

André Haman ◽

...

Keyword(s):

Gene Expression ◽

Transcription Factors ◽

Dna Binding ◽

Rna Polymerase Ii ◽

Protein Interactions ◽

Expression Profiles ◽

Basic Domain ◽

Interaction Mode

ABSTRACT Transcription factors can function as DNA-binding-specific activators or as coactivators. c-Jun drives gene expression via binding to AP-1 sequences or as a cofactor for PU.1 in macrophages. c-Jun heterodimers bind AP-1 sequences with higher affinity than homodimers, but how c-Jun works as a coactivator is unknown. Here, we provide in vitro and in vivo evidence that c-Jun homodimers are recruited to the interleukin-1β (IL-1β) promoter in the absence of direct DNA binding via protein-protein interactions with DNA-anchored PU.1 and CCAAT/enhancer-binding protein β (C/EBPβ). Unexpectedly, the interaction interface with PU.1 and C/EBPβ involves four of the residues within the basic domain of c-Jun that contact DNA, indicating that the capacities of c-Jun to function as a coactivator or as a DNA-bound transcription factor are mutually exclusive. Our observations indicate that the IL-1β locus is occupied by PU.1 and C/EBPβ and poised for expression and that c-Jun enhances transcription by facilitating a rate-limiting step, the assembly of the RNA polymerase II preinitiation complex, with minimal effect on the local chromatin status. We propose that the basic domain of other transcription factors may also be redirected from a DNA interaction mode to a protein-protein interaction mode and that this switch represents a novel mechanism regulating gene expression profiles.

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Transcription Factor Control of Dendrite Targeting via Combinatorial Cell-Surface Codes

10.21203/rs.3.rs-983283/v1 ◽

2021 ◽

Author(s):

Liqun Luo ◽

Qijing Xie ◽

Jiefu Li ◽

Hongjie Li ◽

Namrata Udeshi ◽

...

Keyword(s):

Transcription Factor ◽

Transcription Factors ◽

Cell Surface ◽

Surface Protein ◽

Surface Proteins ◽

Projection Neurons ◽

Cell Surface Protein ◽

Cell Surface Proteins ◽

Cellular Environment ◽

Combinatorial Expression

Abstract Transcription factors are central commanders specifying cell fate, morphology, and physiology while cell-surface proteins execute these commands through interaction with cellular environment. In developing neurons, it is presumed that transcription factors control wiring specificity through regulation of cell-surface protein expression. However, the number and identity of cell-surface protein(s) a transcription factor regulates remain largely unclear1,2. Also unknown is whether a transcription factor regulates the same or different cell-surface proteins in different neuron types to specify their connectivity. Here we use a lineage-defining transcription factor, Acj6 (ref. 3), to investigate how it controls precise dendrite targeting of Drosophila olfactory projection neurons (PNs). Quantitative cell-surface proteomic profiling of wild-type and acj6 mutant PNs in intact developing brains and a proteome-informed genetic screen identified PN surface proteins that execute Acj6-regulated wiring decisions. These include canonical cell adhesion proteins and proteins previously not associated with wiring, such as the mechanosensitive ion channel Piezo—whose channel activity is dispensable for its wiring function. Comprehensive genetic analyses revealed that Acj6 employs unique sets of cell-surface proteins in different PN types for dendrite targeting. Combinatorial expression of Acj6 wiring executors rescued acj6 mutant phenotypes with higher efficacy and breadth than expression of individual executors. Thus, a key transcription factor controls wiring specificity of different neuron types by specifying distinct combinatorial expression of cell-surface executors.

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LYMPHOCYTE MEMBRANE DYNAMICS

Journal of Experimental Medicine ◽

10.1084/jem.134.6.1373 ◽

1971 ◽

Vol 134 (6) ◽

pp. 1373-1384 ◽

Cited By ~ 85

Author(s):

Robert E. Cone ◽

John J. Marchalonis ◽

Ronald T. Rolley

Keyword(s):

Cell Surface ◽

Disc Electrophoresis ◽

Membrane Dynamics ◽

Surface Proteins ◽

Dynamic State ◽

Cellular Respiration ◽

Spleen Cells ◽

Cell Surface Proteins ◽

Before And After

Cell surface proteins of normal and neoplastic lymphocytes were labeled with iodide-125I by lactoperoxidase-catalyzed iodination. Incubation of 125I-labeled iodide cells in vitro resulted in the release of iodinated surface proteins at a rapid rate which was dependent on cellular respiration and protein synthesis. Comparisons by disc electrophoresis showed a marked similarity between urea-soluble surface proteins extracted from iodinated cells and iodinated material released by the cells during in vitro incubation. The rate of release of cell surface proteins from thymus cells was three times faster than that of spleen cells or bone marrow-derived thoracic duct lymphocytes. In addition, different proteins were released at different rates as evidenced by the rate of release of 125I of rabbit anti-mouse immunoglobulin specifically bound to mouse spleen cells and comparisons by disc electrophoresis of urea-soluble iodinated surface proteins extracted from cells before and after incubation. The results suggest that a dynamic state exists at the cell surface. The possible role of the release of cell surface proteins in cell regulation and communication is discussed.

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