Rat myoblast fusion requires metalloendoprotease activity

Couch, Christine; Strittmatter, Warren J.

doi:10.1016/0092-8674(83)90516-0

Cited by 138 publications

(89 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some fusion events require the activity of an endogenous, soluble metalloendoprotease [29,30], whereas participation of serine and thiol proteases in the membrane fusion process are indicated in other cases. The reported conclusions on the role of the proteases in membrane fusion events have been based on finding inhibition of fusion in whole, intact cells treated with thiol-alkylating agents and various protease inhibitors [29-331. Ca2+ is required for most of the fusions reported [l -7, 10, 28, 31 -331, though in one case membrane fusion occurs in the presence of EDTA [33].…”

Section: Discussionmentioning

confidence: 99%

Fusion of rat erythrocytes by membrane-mobility agent A2C depends on membrane proteolysis by a cytoplasmic calpain

Glaser¹,

Kosower²

1986

Eur J Biochem

View full text Add to dashboard Cite

The membrane-mobility agent 2-(2-methoxyethoxy)ethyl-ciJ.-8-(2-octylcyclopropyl)octanoate (A2C) promotes fusion of rat, but not of human, erythrocytes. The difference in fusibility was shown to be correlated with membrane proteolysis, a process induced by Ca2+ in the rat erythrocytes or hemolysate-loaded ghosts, but not in the human cell. Membrane proteolysis is necessary but not sufficient for fusion. Fusion requires both Caz+ and A2C [Kosower, N. S., Glaser, T. and Kosower, E. M. (1983) Proc. Natl Acad. Sci USA 80, 7542-75461.Membrane proteolysis (Ca2 +-dependent) and fusion (Ca2+ and A2C-dependent) requires a CaZ +-activated cytoplasmic thiol protease, as shown by the following observations. (a) In intact rat erythrocytes, proteolysis and fusion are prevented by tho1 alkylation and by inhibitors of Ca2+-dependent thiol proteases. Inhibitors to other proteases have no effect. (b) Erythrocyte ghosts undergo proteolysis and fusion only when loaded with noninhibited hemolysate, irrespective of membrane status (native or alkylated membrane). (c) A partially purified cytosolic enzyme, identified as calpain I, promotes proteolysis in rat erythrocyte ghosts. A2C induces fusion only in such calpain-treated ghosts.Membrane fusion is important for many cellular processes such as fertilization, muscle development, giant cell formation, exocytosis, endocytosis and intracellular exchange of membranes between organelles [l -31. Experimentally certain viruses and chemical agents [4 -81 have been used to achieve in vitro fusion in various systems. The membrane-mobility agent, 2-(2-methoxyethoxy)ethyl-cis-8-(2-octylcyclopropyl)-octanoate (A2C), is an efficient promoter of cell fusion. The agent has been useful in defining stages in the process and in the formulation of a molecular mechanism of membrane fusion [8 -101.In earlier studies we have found differences among erythrocytes of various species (both among avian nucleated and mammalian non-nucleated cells) in the response to A2C, with erythrocytes of some species fusing easily and others either less easily or not at all [ll -121. Rat erythrocytes fuse easily when treated with A2C and Ca2+, whereas human cells do not fuse under these conditions [12]. We have found the difference in fusibility to be correlated with the occurrence of Ca2+-induced membrane protein degradation [13]. Using rat erythrocyte ghosts we have found membrane protein degradation in the presence of Ca2+ and hemolysate. A2C promotes fusion in these ghosts [13].We have now partially purified and defined the protease involved in the membrane proteolysis associated with A2C-induced fusion. In the intact rat erythrocyte, membrane proteolysis (Ca2+ -dependent) or membrane proteolysis and fusion (Ca' + and A2C-dependent) are prevented by inhibitors to Ca2 +-activated, thiol proteases and by thiol alkylation. In Correspondence to N. S . Kosower, Department of Human Genetics, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, lsrael Abbreviations. A2C, 2-(2-methoxyethoxy)ethyl-cis-8-(2-octylcyc1opropy...

show abstract

Section: Discussionmentioning

confidence: 99%

Fusion of rat erythrocytes by membrane-mobility agent A2C depends on membrane proteolysis by a cytoplasmic calpain

Glaser¹,

Kosower²

1986

Eur J Biochem

View full text Add to dashboard Cite

show abstract

“…The effects of metalloproteinase inhibitors on differentiating myoblasts have been studied previously, with some confounding results probably coming from different inhibitor spectrums (Couch and Strittmatter, 1983;Huet et al, 2001). The inhibitor that we used herein, particularly TIMP-2, is MMP-specific, though TIMP-1 inhibits some ADAMs, and these inhibited myotube formation efficiently.…”

Section: Effect Of Metalloproteinase Inhibitors On Myotube Formationmentioning

confidence: 99%

Multifunctional roles of MT1-MMP in myofiber formation and morphostatic maintenance of skeletal muscle

Ohtake

Tojo

Seiki

2006

Journal of Cell Science

114

View full text Add to dashboard Cite

Sequential activation of muscle-specific transcription factors is the critical basis for myogenic differentiation. However, the complexity of this process does not exclude the possibility that other molecules and systems are regulatory as well. We observed that myogenic differentiation proceeded through three distinct stages of proliferation, elongation and fusion, which are distinguishable by their cellular morphologies and gene expression patterns of proliferation- and differentiation-specific markers. Treatment of the differentiating myoblasts with inhibitors of matrix metalloproteinases (MMPs) revealed that MMP activity at the elongation stage is a critical prerequisite to complete the successive myoblast cell fusion. The MMP regulated the myogenic differentiation independently from the genetic program that governs expression of the myogenic genes. Membrane-type 1 matrix metalloproteinase (MT1-MMP) was identified as a major contributor to this checkpoint for morphological differentiation and degraded fibronectin, a possible inhibitory factor for myogenic cell fusion. A MT1-MMP deficiency caused similar myogenic impediments forming smaller myofibers in situ. Additionally, the mutant mice demonstrated some central nucleation of the myofibers typically found in muscular dystrophy and MT1-MMP was found to cleave laminin-2/4 in the basement membrane. Thus, MT1-MMP is a new multilateral regulator for muscle differentiation and maintenance through processing of stage-specific distinct ECM substrates.

show abstract

“…In addition Ca2+-activated neutral proteinase activity has been reported to appear concomitantly with the fusion of rat myoblasts into myotubes, while other proteases such as cathepsin D and plasminogen activator did not show any change in their activities [24]. Interestingly, the fusion of rat myoblasts requires the activity of a neutral metalloendoprotease at the time of fusion, although the relationship between the requirement for Ca2+ in fusion and the activity of the enzyme is at present unknown [25]. Furthermore, recent data indicate that synaptic transmission involves a metalloendoprotease in the pre-synaptic nerve terminal, and that proteolysis may be an important step in the exocytosis of neurotransmitters [26].…”

mentioning

confidence: 99%

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Lucy

1984

FEBS Letters

View full text Add to dashboard Cite

The concept that a direct interaction between Ca2+ and phospholipids is a major factor in membrane fusion reactions is questioned. Attention is drawn to a number of findings on associations between fusion and the proteolysis of membrane proteins. It is proposed that hydrophobic polypeptides, which are functionally comparable to the fusogenic proteins of certain viruses but which are produced in cells by the endogenous proteolysis of membrane and cellular proteins, may induce membrane fusion reactions in vivo.

show abstract

Rat myoblast fusion requires metalloendoprotease activity

Cited by 138 publications

References 22 publications

Fusion of rat erythrocytes by membrane-mobility agent A2C depends on membrane proteolysis by a cytoplasmic calpain

Fusion of rat erythrocytes by membrane-mobility agent A2C depends on membrane proteolysis by a cytoplasmic calpain

Multifunctional roles of MT1-MMP in myofiber formation and morphostatic maintenance of skeletal muscle

Do hydrophobic sequences cleaved from cellular polypeptides induce membrane fusion reactions in vivo?

Contact Info

Product

Resources

About