scholarly journals Anti-actin antibodies. An immunological approach to the myosin-actin and the tropomyosin-actin interfaces

1987 ◽  
Vol 244 (3) ◽  
pp. 571-577 ◽  
Author(s):  
C Mejean ◽  
M Boyer ◽  
J P Labbé ◽  
L Marlier ◽  
Y Benyamin ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Contact Area ◽  
Terminal Part ◽  
Specific Antibodies ◽  
Constant Sequence ◽  
Close Proximity ◽  
Immunological Approach

The topography of the rigor complex between subfragment-1 (S-1) of myosin and actin was investigated by using several specific antibodies directed to well-located sequences in actin. A major contact area for S-1 was characterized in the hydrophilic 18-28 constant sequence, and the variable 1-7 sequence was only found to be in close proximity to the interface. The C-terminal extremity of actin situated around Cys-374 appeared to be included in a region close to the S-1 heavy chain and the N-terminal part of actin. The interaction between tropomyosin and actin was also studied. Neither of the terminal parts of actin were involved in this interaction. Thus, the regions involved in the interactions of S-1 and tropomyosin with actin do not overlap.

scholarly journals Antigenic probes locate binding sites for the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase, aldolase and phosphofructokinase on the actin monomer in microfilaments

1989 ◽  
Vol 264 (3) ◽  
pp. 671-677 ◽  
Author(s):  
C Méjean ◽  
F Pons ◽  
Y Benyamin ◽  
C Roustan
Keyword(s):  
Creatine Kinase ◽  
Conformational Changes ◽  
Contact Area ◽  
Binding Sites ◽  
Arginine Kinase ◽  
Glycolytic Enzymes ◽  
Actin Monomer ◽  
Terminal Part ◽  
Specific Antibodies ◽  
Antigenic Epitopes

The topology of the interfaces between actin monomers in microfilaments and three glycolytic enzymes (glyceraldehyde-3-phosphate dehydrogenase, aldolase and phosphofructokinase) was investigated using several specific antibodies directed against precisely located sequences in actin. A major contact area for glyceraldehyde-3-phosphate dehydrogenase was characterized in a region near residue 103. This interaction altered, by long-range conformational changes, the reactivity of antigenic epitopes in the C-terminal part of actin. The interface between actin and aldolase appeared to involve a sequence around residue 299 in the C-terminal region of actin. The interaction of phosphofructokinase, in contrast, modified the reactivity of all antibodies tested. Finally, the phosphagen kinases arginine kinase and creatine kinase showed no interaction with the microfilament.

scholarly journals Roles of kinesin and kinesin-like proteins in sea urchin embryonic cell division: evaluation using antibody microinjection.

1993 ◽  
Vol 123 (3) ◽  
pp. 681-689 ◽  
Author(s):  
B D Wright ◽  
M Terasaki ◽  
J M Scholey
Keyword(s):  
Cell Division ◽  
Sea Urchin ◽  
Heavy Chain ◽  
Mammalian Cells ◽  
Embryonic Cell ◽  
Mitotic Apparatus ◽  
Specific Antibodies ◽  
Sea Urchin Embryos ◽  
Mitotic Figures

Previous studies suggest that kinesin heavy chain (KHC) is associated with ER-derived membranes that accumulate in the mitotic apparatus in cells of early sea urchin embryos (Wright, B. D., J. H. Henson, K. P. Wedaman, P. J. Willy, J. N. Morand, and J. M. Scholey. 1991. J. Cell Biol. 113:817-833). Here, we report that the microinjection of KHC-specific antibodies into these cells has no effect on mitosis or ER membrane organization, even though one such antibody, SUK4, blocks kinesin-driven motility in vitro and in mammalian cells. Microinjected SUK4 was localized to early mitotic figures, suggesting that it is able to access kinesin in spindles. In contrast to KHC-specific antibodies, two antibodies that react with kinesin-like proteins (KLPs), namely CHO1 and HD, disrupted mitosis and prevented subsequent cell division. CHO1 is thought to exert this effect by blocking the activity of a 110-kD KLP. The relevant target of HD, which was raised against the KHC motor domain, is unknown; HD may disrupt mitosis by interfering with an essential spindle KLP but not with KHC itself, as preabsorption of HD with KHC did not alter its ability to block mitosis. These data indicate that some KLPs have essential mitotic functions in early sea urchin embryos but KHC itself does not.

scholarly journals Antigenic probes locate a serum-gelsolin-interaction site on the C-terminal part of actin

1987 ◽  
Vol 248 (2) ◽  
pp. 359-364 ◽  
Author(s):  
M Boyer ◽  
J Feinberg ◽  
H K Hue ◽  
J P Capony ◽  
Y Benyamin ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Actin Filament ◽  
Muscle Actin ◽  
Terminal Part ◽  
Interaction Site ◽  
Specific Antibodies

The implication of part of the C-terminal of actin (within the 285-375 sequence) in the interaction of serum gelsolin was investigated by the use of specific antibodies. These antibodies were directed against two or three discrete epitopes, one of which was specific for skeletal-muscle actin. Some of these epitopes were found to be near the serum gelsolin-actin interface. Thus it can be assumed that part of the C-terminal of actin is exposed at the barbed end of the actin filament. The interaction between tropomyosin and actin was also studied.

scholarly journals The proteins encoded by the VpreB and lambda 5 pre-B cell-specific genes can associate with each other and with mu heavy chain.

1990 ◽  
Vol 172 (3) ◽  
pp. 969-972 ◽  
Author(s):  
H Karasuyama ◽  
A Kudo ◽  
F Melchers
Keyword(s):  
B Cell ◽  
Heavy Chain ◽  
Light Chain ◽  
Fibroblast Cells ◽  
Specific Antibodies ◽  
Stable Transfectants

The murine pre-B cell-specific genes VpreB and lambda 5, as well as the murine gene for mu heavy chain, were introduced into Ltk- fibroblast cells which normally do not express these genes. Stable transfectants carrying these genes produced the corresponding proteins of 15.5, 21.5, and 75 kD. They secreted the three proteins as a triple complex that could be immunoprecipitated by mu heavy chain-specific antibodies, consisting of one VpreB, one lambda 5, and one mu heavy chain. The mu heavy chain and lambda 5 were disulfide-bonded with each other, while the VpreB protein was noncovalently associated. These experiments proved that the VpreB, lambda 5 and mu H chain proteins can form a heavy/light chain-like heterocomplex.

Studies on the amino acid sequence of heavy chains from rabbit immunoglobulin G

1966 ◽  
Vol 166 (1003) ◽  
pp. 159-175 ◽  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heavy Chain ◽  
Immunoglobulin G ◽  
Light Chains ◽  
Antibody Specificity ◽  
Sequence Heterogeneity ◽  
Specific Antibodies ◽  
Heavy Chains ◽  
Insight Into

It is now generally agreed that the four-chain subunit structure of Immunoglobulins which was first proposed by Porter (1962), accurately represents the gross structure of immunoglobulin G (IgG) and specific antibodies (Fleischman, Porter & Press 1963; Edelman & Gally 1964; Marler, Nelson & Tanford 1964; Nelson et al . 1965). However, an understanding of the structural basis of antibody specificity requires greater insight into the amino acid sequence of the polypeptide chain components of specific antibodies. Isolated light chains from specific antibodies and inert IgG, show a considerable degree of electrophoretic heterogeneity (Edelman & Gally 1964; Cohen & Porter 1964; Poulik 1964). Tryptic peptide maps of light chains (Nelson et al . 1965) have suggested that this heterogeneity may be accounted for by differences in amino acid sequence. This view has received considerable support from the observation that Bence-Jones proteins, which may be regarded as light chains, vary significantly in amino acid sequence (Hilschman & Craig 1965; Milstein 1966; Titani, Whitley & Putman 1966). A similar but less well-defined sequence heterogeneity has been suggested to exist in the heavy chains of specific antibodies (Feinstein 1964). However, the Fc fragment of the heavy chains has been thought to possess a regular amino acid sequence which may be similar, if not identical, among all specific antibodies (Porter 1959; Nelson et al . 1965). This paper summarizes the results of studies on the amino acid sequence of heavy chains and that portion of heavy chain, Fc fragment, which is obtained on treatment of rabbit IgG with papain (Porter 1959). These studies were designed to determine how much of the amino acid sequence of heavy chain could be accounted for by a unique, regular amino acid sequence which was common to most, if not all, IgG antibodies. In addition, attempts were made to locate regions of heavy chains which varied in amino acid sequence. Although structural variants appear to occur among the heavy chains found in non-specific IgG, it would be desirable to know what portion of the heavy chain sequence is invariant among all antibodies. If antibody specificity results from sequence heterogeneity in light and heavy chains, then knowledge of the variant and invariant portions of these chains may provide insight into the nature of specific binding sites in anti-­bodies.

scholarly journals Nuclear localization of the testis determining gene product SRY.

1995 ◽  
Vol 128 (5) ◽  
pp. 737-748 ◽  
Author(s):  
F Poulat ◽  
F Girard ◽  
M P Chevron ◽  
C Gozé ◽  
X Rebillard ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
Gene Product ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Synthetic Peptides ◽  
High Mobility ◽  
Terminal Part ◽  
Nuclear Targeting ◽  
Specific Antibodies ◽  
Localization Signal

We have studied the expression of the human SRY protein (termed p27SRY) in two different cell lines by using specific antibodies. Confocal microscopy enabled us to localize p27SRY precisely in the nucleus in a discrete punctuate pattern. Furthermore, through microinjection experiments, we have demonstrated that the localization of the p27SRY protein into the nucleus was an event involving the NH2-terminal part of the high mobility group (HMG) domain. With the help of several synthetic peptides and various p27SRY mutants, we have characterized a bipartite basic motif in this part of the protein corresponding to a nuclear localization signal. This nuclear localization signal appears to be highly conserved in SRY box- and HMB box-containing proteins, suggesting common properties of nuclear targeting within the HMG box protein family.

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