Effects of concanavalin on the development of sea urchin egg

Lallier, R

doi:10.1016/0014-4827(72)90577-0

Cited by 74 publications

(13 citation statements)

References 10 publications

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“…The fusion of the membrane of cortical granules with the surface membrane has been known as the most remarkable change in the membrane organization (Runnstr6m, 1966;Eddy & Shapiro, 1976;Schroeder, 1979). The number of sites binding concanavalin A also varies considerably in the process after fertilization (Lallier, 1972;. However, these changes all occur a few minutes after insemination.…”

Section: Discussionmentioning

confidence: 99%

Changes in holding and ion‐channel currents during activation of an ascidian egg under voltage clamp

Kozuka

Takahashi

1982

The Journal of Physiology

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SUMMARY1. The unfertilized egg of an ascidian, Hfiocynthia roretzi, was activated by the divalent ionophore A23187 in natural or artificial sea water (nSW or ASW) or by an external solution containing a high concentration of Ca ions (high-Ca ASW) under voltage-clamp condition.2. Activation current began with an abrupt increase in the holding current and decayed relatively slowly with a common time course in various ASWs. Activation current was both Na-and Ca-dependent. The peak time, Tp, and the peak amplitude, D, of the activation current in nSW at 15 'C and -90 mV were 27+4 sec and -1-50 + 0 47 nA, respectively.3. The currents through Na, Ca and anomalous K channels were evoked by test pulses with constant intervals in nSW and high-Sr, high-Ca and high-K ASWs. Na-channel current was enhanced during activation. In contrast, Ca-channel current decreased. In high-Ca, Na-free ASW the Ca current through Na channels increased while the Ca current through Ca channels decreased. The time for the maximum of Na current, Tmax, was (72+ 1-5) x 10 sec at 15°C and index R, the ratio of the maximum amplitude to the amplitude before activation, was 2-31 +0-18 in nSW. The time for the minimum of Ca-channel current, Tmin, was about 70 sec, being almost the same as Tmax of Na current.4. The current through anomalous K channels increased initially and decreased later with a time lag behind the decrease in Ca-channel current.5. Both Tp of activation current and Tmax of Na current were reduced by raising the temperature. Q10 for Tp and Tmax was 2-2 and 2'3, respectively.6. When the egg was activated in ASW containing scorpion toxin, the Na current through normal channels increased strongly while the Na current through toxinmodified channels increased less markedly.7. There was no significant change in the total membrane capacity before and during activation.

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Section: Discussionmentioning

confidence: 99%

Changes in holding and ion‐channel currents during activation of an ascidian egg under voltage clamp

Kozuka

Takahashi

1982

The Journal of Physiology

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“…Con A interfered with fertilization of sea urchin eggs (232), with the induction by antiimmunoglobulins of patch and cap formation on mouse lymphocytes (233), and with phagocytosis by mouse macrophages (234) and rabbit polymorphonuclear leucocytes (235). Inhibition of tumor cell migration by Con A (236) was used in an objective and semiquantitative method for the estimation of subagglutinating amounts of the lectin (237).…”

Section: Other Biological I~rovertiesmentioning

confidence: 99%

The Biochemistry of Plant Lectins (Phytohemagglutinins)

Lis¹,

Sharon²

1973

Annu. Rev. Biochem.

974

236

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“…This conforms to the evolutionary relationships derived from morphological criteria and fossil records (15). By contrast, Con A, like blocking Fab, causes live blastulae to dissociate into single cells (16) and also binds strongly to 22S particles, regardless of genus (unpublished results). Clearly, the Fab-sensitive site is more complex than a lectin-specific glycosylation structure.…”

Section: Figmentioning

confidence: 99%

Characterization of toposomes from sea urchin blastula cells: a cell organelle mediating cell adhesion and expressing positional information.

Noll¹,

Matranga²,

Cervello³

et al. 1985

Proc. Natl. Acad. Sci. U.S.A.

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Cell adhesion in the sea urchin blastula is mediated by a 22S genus-specific glycoprotein complex consisting initially of six 160-kDa subunits that are processed proteolytically as development proceeds. Noncytolytic removal of the 22S particle from the surface with either 2.5% butanol or trypsin renders dissociated cells reaggregation incompetent, and addition restores reaggregation and development. Polyclonal antibodies against the 22S complex prevent reaggregation in a genus-specific manner while monoclonal antibodies stain cell surface structures in a pattern consistent with a code that specifies the position of a cell in the embryo by a unique combination of subunits in its cell adhesion particles. The existence of similar particles in Drosophila and amphibian embryos suggests that these glycoprotein complexes are a general class of organelles, the toposomes, that in the embryo mediate cell adhesion and express positional information.Sea urchin embryos are uniquely suited for the study of cell-cell interaction in embryogenesis because removal of Ca2+ and Mg2' causes them to dissociate into single cells that, upon restoration of these ions, reaggregate spontaneously to reform a developing embryo (1). Reaggregation is blocked in a strictly genus-specific manner by antibodies (or their Fab fragments) against purified membranes or against butanol extracts from purified membranes (2, 3). Equally inhibitory are antibodies raised against the components extracted noncytolytically from live cells with 2.5% (vol/vol) butanol (2). The proteins solubilized by butanol from purified membranes or from the cell surface neutralize the inhibiting antibodies, stimulate reaggregation, and reconstitute cells that had been rendered reaggregation incompetent by noncytolytic extraction with butanol (2).Attempts to purify the active component gave results suggesting that the activity was associated with a large glycoprotein complex. Thus, when the butanol extract was chromatographed on phenyl-Sepharose or DEAE-Sepharose, the reaggregation-promoting activity was eluted as a single peak that in NaDodSO4 gels was resolved into a defined set of glycoproteins ranging from about 70 to 180 kDa that was identical for the two purification methods (4). Here we report that all the cell adhesion activity in sea urchin blastula embryos detectable in our bioassays is indeed the property of an oligomeric glycoprotein particle. Similar particles have been isolated previously from a number of other sea urchin genera (cited in ref. 5). While the biological function of this particle remained obscure, it was found to originate in yolk granules and to undergo developmentally regulated processing into a number of fragments held together by S-S bridges and noncovalent bonds (5).After the studies reported here were completed, strikingly similar glycoprotein complexes were discovered on the surface of imaginal disc cells of Drosophila by screening for monoclonal antibodies with positional specificity (6). The similarity of the results in sea urchins...

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Effects of concanavalin on the development of sea urchin egg

Cited by 74 publications

References 10 publications

Changes in holding and ion‐channel currents during activation of an ascidian egg under voltage clamp

Changes in holding and ion‐channel currents during activation of an ascidian egg under voltage clamp

The Biochemistry of Plant Lectins (Phytohemagglutinins)

Characterization of toposomes from sea urchin blastula cells: a cell organelle mediating cell adhesion and expressing positional information.

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