Subunit interactions in human plasma fibronectin

Robinson, Randall M.; Hermans, Jan

doi:10.1016/0006-291x(84)91017-9

Cited by 13 publications

(9 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The model stipulates that both compact form and expanded form of plasma Fn are relatively spherical in shape; recent calculations made by Hermans showed that this is in fact the case (Hermans, 1985). This model is also consistent with the observations made by Robinson and Hermans (1984) that the two subunits of plasma Fn are folded independently and are closely associated with each other, even after partial reduction of interchain disulfide bridges. On the other hand, recent work by Skorstengaard et al (1986) indicated that the interchain disulfide bridge pattern of plasma Fn is antiparallel, which certainly would affect the way in which the two subunits are arranged with respect to each other.…”

Section: Resultssupporting

confidence: 92%

Evidence that the two amino termini of plasma fibronectin are in close proximity: a fluorescence energy transfer study

Wolff¹,

Lai²

1988

Biochemistry

View full text Add to dashboard Cite

A fluorescence energy transfer technique has been used to study the intramolecular distance between the two amino termini of human plasma fibronectin. The glutamine-3 residue near the amino terminus of each chain was labeled enzymatically with either monodansylcadaverine or monofluoresceinylcadaverine by use of coagulation factor XIIIa. The nonradiative fluorescence energy transfer between the dansyl (donor) and fluorescein (acceptor) pair in the same protein molecule was determined from steady-state fluorescence measurements. On the basis of the transfer efficiency of 78%, the intramolecular distance between two glutamine-3 residues of fibronectin was estimated to be approximately 23 A, suggesting that the two amino termini of plasma fibronectin are in close proximity. High salt, which affects the hydrodynamic properties of the protein, has no effect on the measured distance. The results support the contention that both compact (in low salt) and expanded (in high salt) conformers of fibronectin are relatively spherical in shape.

show abstract

Section: Resultssupporting

confidence: 92%

Evidence that the two amino termini of plasma fibronectin are in close proximity: a fluorescence energy transfer study

Wolff¹,

Lai²

1988

Biochemistry

View full text Add to dashboard Cite

show abstract

“…Carrell, 1983; Robinson & Hermans, 1984; Erickson, Homandberg, & Mosesson, unpublished experiments) and support the conclusion that the Fib II carboxyl-terminal domains contribute to the self-association of PFn.…”

Section: Resultsmentioning

confidence: 63%

“…These carboxyl-terminal regions may mediate noncovalent interchain interactions within individual fibronectin molecules. Sedimentation velocity and molecular-sieving analyses have demonstrated that partially reduced fibronectin, in which the interchain disulfides are cleaved preferentially (Homandberg et al, 1985a), as well as 190-kDa fragments that lack the amino-terminal 29-kDa domain, behave as dimers (Erickson & Carrell, 1983;Robinson & Hermans, 1984;Erickson, Homandberg & Mosesson, unpublished experiments).…”

mentioning

confidence: 90%

Model of fibronectin tertiary structure based on studies of interactions between fragments

Homandberg¹,

Erickson²

1986

Biochemistry

View full text Add to dashboard Cite

Human plasma fibronectin aggregates in solution and is thought to form fibrils on cell surfaces, perhaps by self-associating and by interacting with other components such as proteoglycans. We have localized the self-association domains by testing the ability of various fragments of fibronectin to interact with each other. Complexation between fluorescamine-labeled fragments and unlabeled fragments or whole molecules was assessed by gel filtration high-performance liquid chromatography. The fragments studied included nonoverlapping fragments that are situated on the fibronectin polypeptide chain in the following order, beginning from the amino terminus: the 29-, 50-, 120-, 35-, and 25-kDa fragments, as well as multiple-domain fragments of 72 kDa containing the 29- and 50-kDa segments, a fragment of 150 kDa containing the 120- and 35-kDa segment, a fragment of 190 kDa containing the 120- and 35-kDa segments, a fragment of 190 kDa containing the 50-, 150-, and 25-kDa segments, and a 45-kDa fragment containing the 35-kDa segment. The amino-terminal 29-kDa fragment bound to the carboxyl-terminal heparin-binding (Hep II) 35-kDa fragment as well as the 150- and 190-kDa fragments that contain the 35-kDa segment. On the other hand, carboxyl-terminal 35- and 45-kDa Hep II containing fragments bound to each other as well as to amino-terminal 29- and 72-kDa fragments and to the 190-kDa fragment. Further, the 25-kDa carboxyl-terminal fibrin-binding fragment bound the 190-kDa fragment, the only fragment containing the 25-kDa segment.(ABSTRACT TRUNCATED AT 250 WORDS)

show abstract

“…An alternative hypothesis to explain our results is that the V region affects the association of FN monomers with each other. This segment may provide a FN binding site for antiparallel alignment of monomers (Ehrismann et al, 1982) or a specific conformation required for subunit interactions independent of disulfide bonding (Homandberg et al, 1985;Robinson and Hermans, 1984). Evidence exists for interaction between the COOH-terminal regions of FN monomers and between the COOH-terminal heparin domain and the NH2-terminal fibrin domain (Homandberg and Erickson, 1986).…”

Section: Discussionmentioning

confidence: 99%

Selective secretion of alternatively spliced fibronectin variants.

Schwarzbauer

Spencer

Wilson

1989

The Journal of Cell Biology

View full text Add to dashboard Cite

Abstract. We demonstrate that the alternatively spliced variable (V) region of fibronectin (FN) is required for secretion of FN dimers during biosynthesis. Alternative splicing of the V segment of the rat FN transcript generates three subunit variants (V120, V95, V0) that differ by the inclusion or omission of an additional 120 or 95 amino acids. We are exploring the functions of this segment by expressing variant cDNAs in normal and transformed fibroblasts. Like FN itself, the cDNA-encoded polypeptides (deminectins [DNs]) containing the V120 or V95 segment are efficiently secreted as disulfide-bonded homodimers. However, few homodimers of DNs lacking this region, V0 DNs, are secreted. V0 homodimers do form inside the cell, as demonstrated by biosynthetic analyses of dimer formation and secretion using pulse-chase and time course experiments, but these dimers seldom reach the cell surface and are probably degraded intracellularly.Coexpression of V0 and V120 subunits results in intracellular formation of three types of dimers, V0-V0, V0-V120, and V120-V120, but only the V120-containing dimers are secreted. This selective retention of V0 homodimers indicates that the V region is required for formation and secretion of native FN dimers. In an analogous in vivo situation, we show that plasma FN also lacks V0-V0 dimers and consists of V0-V+ and V+-V+ combinations.Dissection of V region sequences by deletion mapping localizes the major site involved in DN dimer secretion to an 18-amino acid segment within V95. In addition, high levels of dimer secretion can be restored by insertion of V into a heterologous site 10 kD COOH terminal to its normal location. We discuss the potential role of intracellular protein-protein interactions in FN dimer formation. F IBRONECTIN (FN) ~ is an integral part of the extracellular matrix, binding to cells, collagen, proteoglycans, and other macromolecules, and playing an important role in cell adhesion and spreading, cell migration, hemostasis and thrombosis, cell morphology, and cytoskeletal organization, and oncogenic transformation (for review, see Yamada, 1983;Hynes, 1986;McDonald, 1988;Ruoslahti, 1988;Mosher, 1989). Alternative splicing of the FN gene transcript results in cell type specific subunit variation (Schwarzbauer et al., 1983(Schwarzbauer et al., , 1985(Schwarzbauer et al., , 1987b Kornblihtt et ai., 1984 Kornblihtt et ai., , 1985Bernard et al., 1985;Paul et al., 1986;Sekiguchi et al., 1986; Norton and Hynes, 1988;Schwarzbauer, 1989). Three sites of alternative splicing occur in FN: EIHA, EIIIB and the variable (V) region (also known as ED-A, ED-B and IIICS, respectively). The first two are single type III repeats encoded by single exons that are included or skipped during splicing and are found in a subset of cellular FN subunits. Exon subdivision of the V region gives rise to three variants in rat and five in human by splicing within the coding sequences. The three forms in rat are called V0, V95, and V120 to denote the number of extra amino acids included in each var...

show abstract

Subunit interactions in human plasma fibronectin

Cited by 13 publications

References 25 publications

Evidence that the two amino termini of plasma fibronectin are in close proximity: a fluorescence energy transfer study

Evidence that the two amino termini of plasma fibronectin are in close proximity: a fluorescence energy transfer study

Model of fibronectin tertiary structure based on studies of interactions between fragments

Selective secretion of alternatively spliced fibronectin variants.

Contact Info

Product

Resources

About