Studies on lectin activity during myogenesis

Podleski, Thomas R.; Greenberg, I.; Nichols, Sharon

doi:10.1016/0014-4827(79)90307-0

Cited by 26 publications

(7 citation statements)

References 17 publications

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“…In our studies, using the L6 line of myogenic cells, we have found that the agglutination due to electrolectin is blocked by another protein, and evidence for the surface location of this protein has been provided (9). We have suggested that this blocking protein may be identical to another agglutinating protein present in these cells, which we have called myonectin.…”

Section: Introductionmentioning

confidence: 64%

“…As the cells grow to confluency and begin to fuse, both myonectin and p-electrolectin activities increase, but s-electrolectin activity decreases. These changes in activities can represent changes in specific activities of >10-fold (9).…”

Section: Introductionmentioning

confidence: 99%

“…The growth conditions for the L6 cells (15) and primary rat skeletal muscle cultures have been described (9,16), as have the agglutination assays (5,6,9).…”

Section: Introductionmentioning

confidence: 99%

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Distribution and activity of endogenous lectin during myogenesis as measured with antilectin antibody.

Podleski¹,

Greenberg²

1980

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

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Antibodies to electrolectin, a lectin endogenous to embryonic skeletal muscle, have been used to study the distribution of electrolectin during myogenesis in L3 cells and rat primary muscle cultures. Antibody binding is highest to mononucleated cells and is low to myotubes in both systems. Binding is much lower to fibroblasts in the primary cultures. Binding appears to be on the surface of these cells, although evidence is presented for there being binding on the inside of cells as well. When observed on myotubes, binding is generally associated with highly stained patches and in some instances is near regions where fusion may be occurring. In L3 cells, binding sites can be exposed by treating mononucleated cells with trypsin. These results are discussed in terms of their possible role in myogenesis and synaptogenesis. Teichberg et al. (1) discovered and partially characterized a lectin from electric organs and other excitable tissues. This lectin, called electrolectin, caused the agglutination of rabbit erythrocytes and this agglutination was inhibited by galactose-containing sugars. Subsequently, a protein with these properties has been isolated and has been found in several different tissues (2-4).Because this lectin was found in high activities in embryonic skeletal muscle, several laboratories investigated the possibility that electrolectin was involved in the differentiation of skeletal muscle. Although all these studies showed that the activity of electrolectin changed as the muscle cells differentiated, no definitive function for electrolectin has been proven (5-8).In our studies, using the L6 line of myogenic cells, we have found that the agglutination due to electrolectin is blocked by another protein, and evidence for the surface location of this protein has been provided (9). We have suggested that this blocking protein may be identical to another agglutinating protein present in these cells, which we have called myonectin. Because the blocking protein is soluble under our homogenization conditions, its presence in the supernatant fraction can prevent the accurate measurement of the soluble form of electrolectin (s-electrolectin). There is another form of the electrolectin which is bound to subcellular organelles but can be solubilized by sugars containing 3-D-galactose; we have called this particulate form of electrolectin p-electrolectin. All three proteins-i.e., s-electrolectin, p-electrolectin, and myonectin-undergo characteristic changes in activity as the cells differentiate. Myonectin and p-electrolectin activities are very low after the cells are plated into fresh medium, but s-electrolectin activity is high. As the cells grow to confluency and begin to fuse, both myonectin and p-electrolectin activities increase, but s-electrolectin activity decreases. These changes in activities can represent changes in specific activities of >10-fold (9).The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" ...

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Section: Introductionmentioning

confidence: 64%

Section: Introductionmentioning

confidence: 99%

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Distribution and activity of endogenous lectin during myogenesis as measured with antilectin antibody.

Podleski¹,

Greenberg²

1980

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

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“…Although activities promoting myoblast adhesion have not been previously isolated from skeletal muscle cells, activities that agglutinate erythrocytes have been described (22,23). The 16S particle isolated from L6 myoblasts is also a hemagglutinin.…”

Section: Discussionmentioning

confidence: 99%

“…Hemagglutinating activities have been described in muscle cultures (22,23). To test the possibility that the L6 particle is also a hemagglutinin, it was sedimented in a sucrose gradient as described in Fig.…”

Section: Methodsmentioning

confidence: 99%

Role of a 16S glycoprotein complex in cellular adhesion.

Schubert¹,

Lacorbière²

1980

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

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Myogenic cells release into their culture medium a glycoprotein complex that mediates cellular adhesion.In the absence of calcium this complex has a sedimentation value of 16 S. it agegates in the presence of calcium. The 16S material both agglutinates and increases the rate of cell-substratum adhesion of a myoblast variant and inhibits the adhesion of a nerve-like cell line to culture dishes. It-is alsQ a hemagglutinin. The 16S particle is composed of glycbsamitoglycans and several proteins, including fibronectin and collagen. Macromolecules responsible for cellular adhesion are released from cells into their environment. For example, glycoproteins involved in the aggregation of retinal cells bave been isolated from growth-conditioned medium (1,2), and molecules secreted from fibroblast-like cells promote cell-substratum adhesion (3,4 (17), and identifying the GAGs in the individual peaks by enzymatic methods (18). Hydroxyproline was determined by using cells labeled with [14C]proline. The fractions of interest were isolated, hydrolyzed in 6 M HCI, and chromatographed on an amino acid analyzer; the radioactivity in the 4-hydroxyproline and proline peaks was determined.Preparation of Conditioned Medium and SAM. Conditioned medium was prepared from exponentially dividing cells by washing the cells twice in serum-free Hepes-buffered medium and incubating the cells in the same medium for 15 hr at 370C. To prepare SAM-coated dishes, growth-conditioned medium was placed in 35-mm. plastic petri dishes (Falcon) for 18 hr, and then the dishes were washed twice with 0.5 mM ethylene glycol bis(fl-aminoethyl ether)-NN,N',N'-tetraacetic acid (EGTA), three times with water, and once with Hepes medium. After the washing, 2 ml of Hepes medium containing 0.2% bovine serum albumin was added.Adhesion Assays. To assay cell-substratum adhesion, early stationary phase M3A or PC12 cells were labeled with [3H]-leucine (5 MCi/ml; 1 Ci = 3.7 X 1010 becquerels) for 15 hr. The cells were washed three times with Hepes medium containing 0.2% albumin and 0.2-ml aliquots were pipetted into 35-mm SAM-coated plastic petri dishes containing 2 ml of the same medium. At indicated times the dishes were swirled 10 times, the medium was aspirated, and the remaining attached cells were dissolved in Triton X-100 and their isotope content was determined.. The data were plotted as the fraction of input cells that adhered as a function of time. Variation between duplicates was less than 5% (19).Cell aggregation was measured by the disappearance of single cells from an agitated suspension (19, 20). Cells were washed twice in Hepes buffer containing 0.2% bovine serum albumin and added to 0.5-ml aliquots of the test medium made 0.2% in albumin. The cells were agitated on a rotary shaker at 100 rpm and the disappearance of single cells was monitored with a Coulter Counter.The rabbit erythrocytes used for the hemagglutination assays were prepared in two ways. Some were trypsin-treated and fixed with glutaraldehyde; others were trypsin-treated, fixed w...

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Thy‐1‐like immunoreactivity in developing chicken skeletal muscle: Identification of a cross‐reactive slow‐fiber specific molecule that is not Thy‐1

Shahin¹,

Jeffrey²,

Rostas

1990

J of Neuroscience Research

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We investigated the Thy-1-like immunoreactivity during the development of chicken skeletal muscle using a group of monoclonal antibodies raised and characterised against purified chicken brain Thy-1. The immunoreactivity attributable to bona fide Thy-1 in muscle was present in nerves, connective tissue associated with the intrafusal capsule and blood vessels, and the extracellular matrix of the muscle fibres. During development there was no change in the staining of nerves, blood vessels or intrafusal capsules. However, the extracellular staining of muscle first appeared around hatching and gradually increased in intensity reaching maximal levels in the adult. The intensity of staining varied within and between the muscles examined. One of the antibodies (SB1 20.11) recognised an additional molecule that is not Thy-1 and that was localised in the cytoplasm of slow muscle fibres. This immunoreactivity was first detectable at E10 in all myotubes that contained both alkali and acid stable myosin ATPase activity (presumptive slow), but not in those myotubes with only alkali-stable myosin ATPase activity (presumptive fast). Thereafter, the staining increased to a maximum in the newly hatched animal and then decreased until reactivity was undetectable in the adult (greater than 25 weeks). All positive fibres initially stained with a uniform intensity but the time of commencement and the rate of loss of staining was variable. Those fibres that contained both acid stable and acid labile myosin ATPase activity lost the antigen much faster than the fibres containing only acid-stable myosin ATPase activity, which also tended to increase in intensity for a longer period. These may represent, respectively, the slow tonic type III fibres and the slow twitch type I fibres classified by Barnard et al. (1982).

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Studies on lectin activity during myogenesis

Cited by 26 publications

References 17 publications

Distribution and activity of endogenous lectin during myogenesis as measured with antilectin antibody.

Distribution and activity of endogenous lectin during myogenesis as measured with antilectin antibody.

Role of a 16S glycoprotein complex in cellular adhesion.

Thy‐1‐like immunoreactivity in developing chicken skeletal muscle: Identification of a cross‐reactive slow‐fiber specific molecule that is not Thy‐1

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