scholarly journals Structural Protein 4.1 in the Nucleus of Human Cells: Dynamic Rearrangements during Cell Division

1997 ◽  
Vol 137 (2) ◽  
pp. 275-289 ◽  
Author(s):  
Sharon Wald Krauss ◽  
Carolyn A. Larabell ◽  
Stephen Lockett ◽  
Philippe Gascard ◽  
Sheldon Penman ◽  
...  
Keyword(s):  
Cell Division ◽  
Nuclear Matrix ◽  
Mammalian Cells ◽  
Matrix Protein ◽  
Protein Isoforms ◽  
Red Cell ◽  
Structural Protein ◽  
Red Cell Membrane ◽  
Protein 4.1 ◽  
Alternative Mrna Splicing

Structural protein 4.1, first identified as a crucial 80-kD protein in the mature red cell membrane skeleton, is now known to be a diverse family of protein isoforms generated by complex alternative mRNA splicing, variable usage of translation initiation sites, and posttranslational modification. Protein 4.1 epitopes are detected at multiple intracellular sites in nucleated mammalian cells. We report here investigations of protein 4.1 in the nucleus. Reconstructions of optical sections of human diploid fibroblast nuclei using antibodies specific for 80-kD red cell 4.1 and for 4.1 peptides showed 4.1 immunofluorescent signals were intranuclear and distributed throughout the volume of the nucleus. After sequential extractions of cells in situ, 4.1 epitopes were detected in nuclear matrix both by immunofluorescence light microscopy and resinless section immunoelectron microscopy. Western blot analysis of fibroblast nuclear matrix protein fractions, isolated under identical extraction conditions as those for microscopy, revealed several polypeptide bands reactive to multiple 4.1 antibodies against different domains. Epitope-tagged protein 4.1 was detected in fibroblast nuclei after transient transfections using a construct encoding red cell 80-kD 4.1 fused to an epitope tag. Endogenous protein 4.1 epitopes were detected throughout the cell cycle but underwent dynamic spatial rearrangements during cell division. Protein 4.1 was observed in nucleoplasm and centrosomes at interphase, in the mitotic spindle during mitosis, in perichromatin during telophase, as well as in the midbody during cytokinesis. These results suggest that multiple protein 4.1 isoforms may contribute significantly to nuclear architecture and ultimately to nuclear function.

Emp is a component of the nuclear matrix of mammalian cells and undergoes dynamic rearrangements during cell division

2006 ◽  
Vol 342 (4) ◽  
pp. 1040-1048 ◽  
Author(s):  
Shashi Bala ◽  
Ajay Kumar ◽  
Shivani Soni ◽  
Sudha Sinha ◽  
Manjit Hanspal
Keyword(s):  
Cell Division ◽  
Nuclear Matrix ◽  
Mammalian Cells

scholarly journals Protein 4.1 is a component of the nuclear matrix of mammalian cells

1995 ◽  
Vol 312 (3) ◽  
pp. 871-877 ◽  
Author(s):  
G De Cárcer ◽  
M J Lallena ◽  
I Correas
Keyword(s):  
Nuclear Matrix ◽  
Mammalian Cells ◽  
Polyclonal Antibodies ◽  
Cell Types ◽  
Membrane Skeleton ◽  
Dnase I ◽  
Common Element ◽  
Nuclear Speckles ◽  
Protein 4.1 ◽  
Sequential Treatments

Protein 4.1 is a major component of the erythrocyte membrane skeleton that promotes the interaction of spectrin with actin and links the resulting complex network to integral membrane proteins. Here we analyse the distribution of different 4.1 proteins within the nucleus of mammalian cells. Nuclear matrices have been prepared from Madin-Darby canine kidney (MDCK) and HeLa cells and protein fractions isolated at each step of the purifications have been analysed by immunoblotting using characterized polyclonal antibodies against protein 4.1. Two 4.1 polypeptides of M(r) approximately 135,000 and 175,000 are extracted after DNase I digestion and 0.25 M ammonium sulphate treatments, suggesting that they may be associated with chromatin. Interestingly, nuclear matrices isolated after DNase I digestion and sequential treatments with increasing ionic strength contain a third 4.1 polypeptide of M(r) approximately 75,000 (4.1p75), suggesting that it is a component of the nuclear matrix. Immunoblot analyses of nuclear matrices isolated from different cell types and species indicate that 4.1p75 is a common element of the nuclear matrix of mammalian cells. Moreover, 4.1p75 distributes to typical nuclear speckles which are enriched with the spliceosome assembly factor SC35, as revealed by double-label immunofluorescence analyses. Protein 4.1p75 might be an anchoring element of the nucleoskeleton, playing a role similar to that described for the erythroid protein 4.1 in red blood cells.

Red cell membrane alteration involving protein 4.1 and protein 3 in a case of recessively inherited haemolytic anaemia

2009 ◽  
Vol 38 (5) ◽  
pp. 447-455 ◽  
Author(s):  
Laurette Morlé ◽  
Brigitte Pothier ◽  
Nicole Alloisio ◽  
Marie-Thérése Ducluzeau ◽  
Sandra Marques ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Haemolytic Anaemia ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Protein 4.1

Localization of NuMA protein isoforms in the nuclear matrix of mammalian cells

1994 ◽  
Vol 29 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Changqing Zeng ◽  
Dacheng He ◽  
B. R. Brinkley
Keyword(s):  
Nuclear Matrix ◽  
Mammalian Cells ◽  
Protein Isoforms

scholarly journals Phosphorylation-related accumulation of the 125K nuclear matrix protein mitotin in human mitotic cells

1990 ◽  
Vol 95 (1) ◽  
pp. 59-64
Author(s):  
N.Z. Zhelev ◽  
I.T. Todorov ◽  
R.N. Philipova ◽  
A.A. Hadjiolov
Keyword(s):  
Nuclear Matrix ◽  
Mammalian Cells ◽  
Matrix Protein ◽  
Specific Protein ◽  
S Phase ◽  
Short Term ◽  
Nuclear Matrix Protein ◽  
Complex Events ◽  
G2 Phase ◽  
Mitotic Cells

The preparation of mammalian cells for entry into mitosis is related to a cascade of G2 phase phosphorylations of several nuclear proteins driven by mitosis-specific protein kinases. Using a monoclonal antibody we have identified previously in mammalian cells a 125K/pI6.5 protein, associated with the nuclear matrix, and markedly increased in mitotic cells, which was named ‘mitotin’. Here, we show by short-term [35S]methionine labeling of cell cycle synchronized cells that this protein is synthesized at comparable rates throughout interphase. However, upon cycloheximide block of protein synthesis mitotin labeled during S phase is rapidly degraded, while the degradation of mitotin labeled during late G2 phase is abolished, resulting in its net and marked increase. The accumulation of mitotin in premitotic and mitotic cells is related to its phosphorylation and the metabolic stability of its two phosphorylated forms. The metabolic stabilization and accumulation of a nuclear matrix protein upon phosphorylation suggests the operation of a novel mechanism among the complex events preparing the cell for mitosis.

scholarly journals Effect of hemoglobin oxidation products on the stability of red cell membrane skeletons and the associations of skeletal proteins: correlation with a release of hemin

Blood ◽  
1990 ◽  
Vol 76 (10) ◽  
pp. 2125-2131 ◽  
Author(s):  
P Jarolim ◽  
M Lahav ◽  
SC Liu ◽  
J Palek
Keyword(s):  
Cell Membrane ◽  
Molecular Mechanisms ◽  
Membrane Skeleton ◽  
Oxidation Products ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Protein 4.1 ◽  
Stabilizing Effect ◽  
The Stability ◽  
Membrane Skeletons

Oxidative injury to hemoglobin (Hb) leads to formation of methemoglobin (MetHb), reversible hemichromes (rHCRs), and irreversible hemichromes (iHCRs). iHCRs precipitate and form Heinz bodies that attach to the red cell membrane causing injury that leads to hemolysis. The molecular mechanisms of this membrane damage have not been fully elucidated. We have studied the effect of Hb oxidation products on the mechanical stability of red cell membrane skeletons and the associations of membrane skeletal proteins. Hb and MetHb stabilized the isolated membrane skeletons, whereas further oxidation to rHCRs abolished this stabilizing effect. Crude iHCRs prepared by phenylhydrazine oxidation of Hb destabilized membrane skeletons by decreasing formation of the spectrin-protein 4.1-actin complex, the effect similar to that of pure hemin. Whereas virtually no hemin was released from Hb and MetHb, high concentrations of hemin were released from crude iHCR preparations. After removal of this hemin fraction by Dowex resin, the iHCRs lost their destabilizing effect. We conclude that as the oxidation of Hb proceeds, the stabilizing effect of Hb on the membrane skeleton is gradually lost and the deleterious effect increases. The destabilization of the red cell membrane skeleton in the presence of crude iHCR is caused by release of hemin, which lowers the stability of membrane skeleton by weakening the spectrin-protein 4.1-actin interaction.

scholarly journals Protein 4.1 deficiency associated with an altered binding to the spectrin-actin complex of the red cell membrane skeleton.

1994 ◽  
Vol 94 (4) ◽  
pp. 1651-1656 ◽  
Author(s):  
F Lorenzo ◽  
N Dalla Venezia ◽  
L Morlé ◽  
F Baklouti ◽  
N Alloisio ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Membrane Skeleton ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Protein 4.1
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