Preparation of slime sheath from Dictyostelium discoideum

Smith, E.R.

doi:10.1016/0378-1097(79)90112-5

Cited by 5 publications

(10 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The slugs of D. discoideum strain WS380B [25] were prepared as previously described [28] and allowed to migrate across the petri plate towards a point light source [29] for 4–5 days. By this time all the slugs had completely traversed the plate, leaving it covered with a layer of sheath essentially free of cells.…”

Section: Methodsmentioning

confidence: 99%

Cellulose‐binding modules from extracellular matrix proteins of Dictyostelium discoideum stalk and sheath

Wang

Slade

Gooley³

et al. 2001

European Journal of Biochemistry

View full text Add to dashboard Cite

Cellulose-binding modules (CBMs) of two extracellular matrix proteins, St15 and ShD, from the slime mold Dictyostelium discoideum were expressed in Escherichia coli. The expressed proteins were purified to . 98% purity by extracting inclusion bodies at pH 11.5 and refolding proteins at pH 7.5. The two refolded CBMs bound tightly to amorphous phosphoric acid swollen cellulose (PASC), but had a low affinity toward xylan. Neither protein exhibited cellulase activity. St15, the stalk-specific protein, had fourfold higher binding affinity toward microcrystalline cellulose (Avicel) than the sheath-specific ShD CBM. St15 is unusual in that it consists of a solitary CBM homologous to family IIa CBMs. Sequence analysis of ShD reveals three putative domains containing: (a) a C-terminal CBM homologous to family IIb CBMs; (b) a Pro/ Thr-rich linker domain; and (c) a N-terminal Cys-rich domain. The biological functions and potential role of St15 and ShD in building extracellular matrices during D. discoideum development are discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

Cellulose‐binding modules from extracellular matrix proteins of Dictyostelium discoideum stalk and sheath

Wang

Slade

Gooley³

et al. 2001

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…Standard conditions were used for the growth of D. discoideum amoebae and the preparation of migrating slugs (18,19). Sheath, sheath extracts, and slug cell extracts were prepared as previously described (3).…”

Section: Methodsmentioning

confidence: 99%

“…Although numerous roles for the sheath have been suggested, evaluation of these proposals has been hampered by the lack of information concerning the composition of the sheath. It contains cellulose fibrils (1) in a highly proteinaceous matrix (5,18), and recent work with monoclonal antibodies (mAbs) has demonstrated shared antigenic determinants on a large number of prespore cell surface and extracellular matrix proteins (3; Grant et al, manuscript in preparation). Furthermore, there are a small number of specific cell surface proteins which are also apparently in the sheath, i.e., have cellular and extracellular forms.…”

mentioning

confidence: 99%

A polymorphic, prespore-specific cell surface glycoprotein is present in the extracellular matrix of Dictyostelium discoideum.

Grant¹,

Welker²,

Williams³

1985

Mol. Cell. Biol.

View full text Add to dashboard Cite

Polymorphisms of a major developmentally regulated prespore-specific protein (PsA) in Dictyostelium discoideum slugs are described. These polymorphisms allowed discrimination between PsA (found on the cell surface and in the extracellular matrix) and a similar extracellular but nonpolymorphic protein, ShA. The two proteins were also distinguished by their differing reactivities with a range of monoclonal antibodies and by their sensitivity to release from the sheath with cellulase. The results are discussed in terms of the molecular and genetic relationships between the cell surface and the extracellular matrix during development.Interactions between the cell surface and the extracellular matrix have been proposed to play an important role in developmental processes (e.g., sea urchin blastulation [6,10]). In some cases (e.g., fibronectin), there are distinct cellular and extracellular forms of the molecules proposed to be involved in these interactions, raising questions concerning the structural and functional relationships between the cell surface and the extracellular matrix. Consequently, elucidation of the biochemical similarities and differences between cellular and extracellular molecules is a necessary prerequisite to resolve how such interactions occur.The cellular slime mold Dictyostelium discoideum has been used extensively as a model system for the study of a wide range of developmental processes (see reference 9). During development, individual vegetative amoebae aggregate to form a multicellular mass which is then covered throughout the developmental process by a thin celluloseprotein sheath or extracellular matrix (16, 17). Although numerous roles for the sheath have been suggested, evaluation of these proposals has been hampered by the lack of information concerning the composition of the sheath. It contains cellulose fibrils (1) in a highly proteinaceous matrix (5, 18), and recent work with monoclonal antibodies (mAbs) has demonstrated shared antigenic determinants on a large number of prespore cell surface and extracellular matrix proteins (3; Grant et al., manuscript in preparation). Furthermore, there are a small number of specific cell surface proteins which are also apparently in the sheath, i.e., have cellular and extracellular forms.The most prominent of these was a 32-kilodalton (kDa) antigen whose cellular and extracellular forms were immunochemically distinguishable. It was not determined whether this was due to (i) alternate processing pathways of a single precursor, (ii) similar processing of unrelated precursors, or (iii) the existence of related but genetically distinct proteins.In this work we demonstrate, using genetic (13, 22), immunochemical, and biochemical criteria, that there are two 32-kDa proteins: one (termed PsA) which is common to * Corresponding author.

show abstract

“…The low pH of the substrate surface is unlikely to affect the pH within the cells as Kay et al (1986) have shown. One possibility is that there are proteases in the slime sheath among the many different proteins Smith & Williams (1979) found there, and lowering the pH at the contact surface might be more favourable for inducing their proteolytic activity. Furthermore, it is known that slime moulds secrete proteases in large quantities and they are acid proteases, with highest activity at low pH values (North & Harwood, 1979;North, 1982).…”

Section: Acidmentioning

confidence: 99%

Proteolysis and orientation in Dictyostelium slugs

Bonner

1993

Journal of General Microbiology

View full text Add to dashboard Cite

It has been long known that the migrating slugs of the cellular slime moulds are highly sensitive to their environment and orient towards light and in temperature and chemical gradients. There is considerable evidence from past work that these orientations are governed by NH, which affects the rate of movement of cells within the slug with such precision that orientation to the external stimuli is achieved. In order to test this hypothesis further, various ways to alter the internal NH, concentration were devised. Substances that either increased or decreased proteolysis were applied to one side of the tip of a slug, thereby affecting its orientation. Some of the treatments strongly support the role of internally produced NH, in orientation, and all the treatments produce results that are consistent with the hypothesis.

show abstract

Preparation of slime sheath from Dictyostelium discoideum

Cited by 5 publications

References 5 publications

Cellulose‐binding modules from extracellular matrix proteins of Dictyostelium discoideum stalk and sheath

Cellulose‐binding modules from extracellular matrix proteins of Dictyostelium discoideum stalk and sheath

A polymorphic, prespore-specific cell surface glycoprotein is present in the extracellular matrix of Dictyostelium discoideum.

Proteolysis and orientation in Dictyostelium slugs

Contact Info

Product

Resources

About