Three-dimensional solution structure of Acanthamoeba profilin-I

Vinson, VK; Sj, Archer; Lattman, Eaton E.; Pollard, T.D.; Da, Torchia

doi:10.1083/jcb.122.6.1277

Cited by 77 publications

(67 citation statements)

References 36 publications

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“…13,1993 on polyproline, argues that these mutations are having local rather than global effects. The three-dimensional structure of Acanthamoeba profilin (obtained by nuclear magnetic resonance spectroscopy [37]) does not immediately provide an explanation of our results but does not rule out that they could be due to local effects. Further discussion of the structural implications of our mutations is forthcoming in a paper on the X-ray crystal structure of Acanthamoeba profilin (2).…”

Section: Discussionmentioning

confidence: 66%

Mutational analysis of yeast profilin.

Haarer¹,

Petzold²,

Brown³

1993

Mol. Cell. Biol.

104

116

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We have mutated two regions within the yeast profilin gene in an effort to functionally dissect the roles of actin and phosphatidylinositol 4,5-bisphosphate (PIP2) binding in profilin function. A series of truncations was carried out at the C terminus of profilin, a region that has been implicated in actin binding. Removal of the last three amino acids nearly eliminated the ability of profilin to bind polyproline in vitro but had no Profilin is a low-molecular-size (12 to 15 kDa) protein that interacts with actin (16,30). Profilin can also bind to the acidic phospholipid L-a-phosphatidylinositol 4,5-bisphosphate (PIP2) and to a lesser extent, phosphatidylinositol monophosphate (23). It has been proposed that interaction with PIP2 may regulate the availability of profilin for interaction with actin (23). Alternatively, profilin may be present to prevent the cleavage of PIP2 by phospholipase C-yl (PLC); such inhibition can be overcome by phosphorylation of PLC (13,14,26), an event that can occur after stimulation of various growth factor receptor tyrosine kinases (39). Thus, activation of PLC by tyrosine kinase receptors could initiate signaling cascades by overcoming the profilin block, resulting in cleavage of PIP2 into the second messengers inositol triphosphate and diacylglycerol.In the yeast Saccharomyces cerevisiae, profilin is required (18) for the proper organization of the actin cytoskeleton into actin cables that generally run longitudinally through the cell and cortical actin spots that occur at regions of active growth (1,22 also known as SRV2 [9]) provided interesting links between the signal transduction machinery and cytoskeletal maintenance and reorganization. Adenylate cyclase-associated protein (hereafter referred to as Cap/Srv2p, and not to be confused with actin-capping protein subunits, encoded by the CAPI and CAP2 genes [3]) appears to be a bifunctional protein, apparently playing a role in the RAS-mediated activation of adenylate cyclase (however, see reference 40) and providing other functions that, when defective, result in abnormalities that are somewhat similar to the defects of a profilin-deficient strain (11,18,38). It is these latter defects that are suppressed by overexpression of profilin. We have found that the ability of two Acanthamoeba isoforms of profilin to suppress the latter defects of Cap/Srv2p correlates with their ability to bind PIP2 (38). This finding suggests that Cap/Srv2p as well as profilin may interact with the signaling pathway that involves PIP2 cleavage. Although little is known about PIP2 signaling in yeast cells, the observation that PIP2 is essential to growth (34) is an indication that it plays an important role. At our present level of knowledge, it is possible that both Cap/Srv2p and profilin are exerting effects on, or are being regulated by, actin and/or PIP2 and related elements. To address these questions, and in an attempt to dissect the known properties of profilin, we have sought to specifically alter profilin's ability to interact with actin or P...

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Section: Discussionmentioning

confidence: 66%

Mutational analysis of yeast profilin.

Haarer¹,

Petzold²,

Brown³

1993

Mol. Cell. Biol.

104

116

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“…X-ray crystallography is being applied to Acanthamoeba profilin-I [ll] and the bovine profilinl actin complex [12,13]. Torchia and co-workers have reported NMR assignments, secondary structure elements, and a medium resolution tertiary structure for Acanthamoeba profilin-I [14,15]. Overall, the tertiary structures of human proBlin [lo] and Acanthamoeba profilin-I [ 151 are quite similar.…”

Section: Fos-b)mentioning

confidence: 99%

Relaxation study of the backbone dynamics of human profilin by two‐dimensional ¹H‐¹⁵N NMR

et al. 1993

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The dynamic properties of 111 backbone HN sites in uncomplexed human profilin, a protein of 139 residues, have been characterized by two‐dimensional inverse‐detected 1H‐15N NMR spectroscopy. Heteronuclear {1H}‐15N nuclear Overhauser effects and 15N longitudinal and transverse relaxation rates have been analyzed in terms of model‐free spectral density functions and exchange contributions to transverse relaxation rates. Relatively high mobilities on the nanosecond timescale are observed for Asp26 and Ser27, which form part of a loop connecting β‐strands A and B, and for Thr92 through Ala95, which are in a loop connecting β‐strands E and F. Significant exchange contributions, indicative of motions on the microsecond to millisecond timescale, have been obtained for 30 residues. These include Leu77, Asp80 and Gly81 of a loop between β‐strands D and E, Ser84 and Met85 of β‐strand E, Gly121 of a loop connecting β‐strand G and the C‐terminal helix, and Gln138, which is next to the C‐terminal residue Tyr139. Some of the regions showing high flexibility in profilin are known to be involved in poly‐L‐proline binding.

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“…Similarly, the unusual residues Asn98 and Leu99 were located between the proposed location of the sixth and seventh P-sheets. It has been proposed that the highly conserved region that interacts with PIP, is rich in basic residues Vinson et al, 1993). An equivalent of this region was located between amino acids 83 and 97 in the bean sequence.…”

Section: Sequence Structural Analysismentioning

confidence: 99%

Purification, Characterization, and cDNA Cloning of Profilin from Phaseolus vulgaris

et al. 1995

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Profilin from common bean (Phaseolus vulgaris 1.) was purified to homogeneity by poly-i-Pro affinity chromatography and gel filtration. The hypocotyl and symbiotic root nodule protein was detected as a single isoform with a 14.4-kD molecular mass and an isoelectric point of 5.3. Partia1 amino acid and DNA sequencing of a full-length cDNA clone confirmed its identity as profilin. An antibody generated against the purified protein binds to a protein with the same molecular mass in leaves and nodules. Immunolocalization of the protein showed a diffuse distribution in the cytoplasm of hypocotyls and nodules but enhanced staining at the vascular bundles. The strong identity of the sequence among the profilins of birch, maize, and bean suggests that it may play an important role in the signal transduction mechanism of plant cells and plantbacterial symbioses.

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Three-dimensional solution structure of Acanthamoeba profilin-I

Cited by 77 publications

References 36 publications

Mutational analysis of yeast profilin.

Mutational analysis of yeast profilin.

Relaxation study of the backbone dynamics of human profilin by two‐dimensional ¹H‐¹⁵N NMR

Purification, Characterization, and cDNA Cloning of Profilin from Phaseolus vulgaris

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Three-dimensional solution structure of Acanthamoeba profilin-I

Cited by 77 publications

References 36 publications

Mutational analysis of yeast profilin.

Mutational analysis of yeast profilin.

Relaxation study of the backbone dynamics of human profilin by two‐dimensional 1H‐15N NMR

Purification, Characterization, and cDNA Cloning of Profilin from Phaseolus vulgaris

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Product

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Relaxation study of the backbone dynamics of human profilin by two‐dimensional ¹H‐¹⁵N NMR