Actin-gelsolin interactions. Evidence for two actin-binding sites.

199

176

Section: Discussionmentioning

confidence: 96%

“…A larger secreted form is readily isolated from blood plasma (Harris and Gooch, 1981). In addition to its severing activity, it accelerates actin polymerization by forming a stable nucleating complex with two actin monomers (Bryan and Kurth, 1984;Doi and Frieden, 1984;Weeds et al, 1986b).…”

mentioning

confidence: 99%

Expression of human plasma gelsolin in Escherichia coli and dissection of actin binding sites by segmental deletion mutagenesis.

Way

Gooch

Pope

et al. 1989

199

176

“…The changes from their method were: (a) the first DEAE-Sephacel step (in the presence of calcium) was done as a "batch" step rather than in a column; and (b) the fractions ~ from the DEAE-Sephacel column (in the presence of EGTA) with 0-0.5 M NaC1 were analyzed for gelsolin by dot blots using a mAb to gelsolin and a peroxidase-labeled secondary antibody. The activity of the gelsolin was assayed by the change in fluorescence of NBD-actin upon binding gelsolin under non-polyrnerizing conditions (Bryan and Kurth, 1984;Coud and Kora, 1985; calibration perl~mned by Dr. A. Weber, University of Pennsylvania, Philadelphia, PA). The gelsolin was stored at -800C or diluted 1:1 with ethylene glycol and stored at -20oC.…”

mentioning

confidence: 99%

Thymosin beta 4 sequesters the majority of G-actin in resting human polymorphonuclear leukocytes.

Cassimeris

Safer

Nachmias

et al. 1992

143

108

Abstract. Thymosin/34 (T134), a 5-kD peptide which binds G-actin and inhibits its polymerization (Safer, D., M. Elzinga, and V. T. Nachmias. 1991. J. , appears to be the major G-actin sequestering protein in human PMNs. In support of a previous study by Hannappel, E., and M.Van Kampen (1987. J. Chromatography. 397:279-285), we find that T/34 is an abundant peptide in these cells. By reverse phase HPLC of perchloric acid supernatants, human PMNs contain ,o169 fg/cell • 90 fg/ceU (SD), corresponding to a cytoplasmic concentration of ,o149 • 80.5 t~M. On non-denaturing polyacrylamide gels, a large fraction of G-actin in supernatants prepared from resting PMNs has a mobility similar to the

“…ELSOLIN is a multifunctional actin-binding protein which was first identified in rabbit macrophages and subsequently found in a wide variety of vertebrate cells (Yin and Stossel, 1979;Yin et al, 1981;Stossel et al, 1985;Carron et al, 1986;Nodes et al, 1987). Gelsolin binds actin monomers, nucleates actin filament growth, and caps the fast-growing end of actin filaments, thus preventing actin monomer exchange (Bryan and Kurth, 1984;Janmey et al, 1985;Byran and Coluccio, 1985;Stossel et al, 1985). In addition, it severs actin filaments by nonproteolytically breaking the bond between actin monomers in a filament.…”

mentioning

confidence: 99%

Genomic organization and biosynthesis of secreted and cytoplasmic forms of gelsolin

Kwiatkowski

Mehl

1988

151

Abstract. Gelsolin is an actin regulatory protein which is unique among vertebrates in that it is found as both an intrinsic cytoplasmic protein and as a secreted plasma protein. We demonstrate that plasma and cytoplasmic gelsolins are derived by alternative transcriptional initiation sites and message processing from a single gene 70 kb long, containing at least 14 exons. Their message and amino acid sequences are identical except at the 5' end/NH2 termini. The cytoplasmic-specific 5' sequence is derived from two exons that encode untranslated sequence, while the plasma message-specific 5' sequence is derived from a single exon that encodes untranslated sequence, the signal peptide, and the first 21 residues of the plasma protein. The two transcriptional initiation sites are separated by >t32 kb. Biosynthetic and RNase protection studies indicate that a number of cell types make both plasma and cytoplasmic gelsolin in widely varying amounts and ratios.