38 research outputs found
The Sec14 <sup>G266D</sup> protein can provide the essential function of Sec14.
<p>Serial dilutions of cells cultured at 25°C and then plated and grown at 25°C and 37°C for 3 days. <i>A</i>, wild type, <i>sec14<sup>ts</sup></i> and <i>sec14<sup>ts</sup> rpn4</i>Δ. <i>B</i>, The <i>sec14<sup>ts</sup></i> strain transformed with either empty vector, a plasmid carried at low copy (ARS/CEN) containing wild type Sec14, or a high copy (2 μ) plasmid containing Sec14<sup>G266D</sup>.</p
Effect of temperature on Sec14 and Sec14 <sup>G266D</sup> protein levels.
<p><i>A</i>, the <i>sec14<sup>ts</sup></i> cells were transformed with a plasmid expressing Sec14 containing an N-terminal T7 epitope, untagged Sec14, or empty vector. <i>SEC14</i> expression was driven by the constitutive <i>GPD1</i> promoter. Cells were grown in solution at 25°C to mid-logarithmic phase, and serial dilutions of identical numbers of cells were spotted onto plates and incubated at 37°C for two days. <i>B</i>, cells expressing T7-Sec14 or Sec14<sup>G266D</sup> were grown to mid-logarithmic phase at 25°C, with a subset shifted to 37°C for 2 hrs. Cells were disrupted by three passes through a French press and membranes were separated from soluble proteins by differential centrifugation. Proteins in each fraction were separated by SDS-PAGE, transferred to PVDF membrane, and western blots were performed. In the blots shown 10 fold more protein extract was loaded in each Sec14<sup>G266D</sup> lane compared to extracts containing wild type Sec14 for blots versus the T7 epitope due to protein expression level differences.</p
Membranes accumulate in growing cells expressing Sec14<sup>G266D</sup>.
<p>Wild type cells and <i>sec14<sup>ts</sup></i> cells containing empty vector, a vector expressing wild type Sec14 on a low copy plasmid, or Sec14<sup>G266D</sup> on a high copy (2 μ) plasmid, were grown at 25°C to mid-logarithmic phase and an aliquot transferred to 37°C for 1 hr followed by incubation in 1.5% KMnO<sub>4</sub>, 1% sodium periodate, and then 1% NH<sub>4</sub>Cl subsequent to embedding and viewing by transmission electron microscopy.</p
Known vesicular trafficking pathways are still aberrant in growing cells expressing Sec14<sup>G266D</sup>.
<p>The <i>sec14<sup>ts</sup></i> strain transformed with either empty vector, a plasmid carried at low copy (ARS/CEN) containing wild type Sec14, or a high copy (2 μ) plasmid containing Sec14<sup>G266D</sup> were grown at 25°C to mid-logarithmic phase and then transferred to 37°C for 1 hr subsequent to determination of: <i>A</i>, invertase secretion (mean ± SE of three separate experiments performed in duplicate), <i>B</i>, or internal retention of Bgl2 at 2 and 16 hrs, similar results were seen at both time point with the 2 hr time point shown. <i>C</i>, the <i>sec14<sup>ts</sup></i> strain containing plasmid borne GFP-Snc1 was transformed with either empty vector, a plasmid carried at low copy (<i>ARS/CEN</i>) containing wild type Sec14, or a high copy (2 μ) plasmid containing Sec14<sup>G266D</sup>. Cells were grown at 25°C to mid-logarithmic phase and then transferred to 37°C for 2 hrs. The localization of GFP-Snc1 was determined by fluorescence microscopy in live cells. <i>D</i>, The strains were grown at 25°C to mid-logarithmic phase and then transferred to 37°C for 15 min prior to the addition of FM4-64. The trafficking of FM4-64 in live cells was visualized by fluorescence microscopy.</p
<i>sec14<sup>ts</sup></i> suppressing gene deletions.
<p><i>sec14<sup>ts</sup></i> suppressing gene deletions.</p
Fus-Mid-GFP and
<p><b>Pma1 localization is defective in </b><b><i>sec14<sup>ts</sup></i></b><b> cells and restored by expression of Sec14<sup>G266D</sup>. </b><i>A, sec14<sup>ts</sup></i> cells expressing Fus-Mid-GFP and also containing empty vector, a vector expressing wild type Sec14 on a low copy plasmid, or Sec14<sup>G266D</sup> on a high copy (2 μ) plasmid, were grown at 25°C in 1% raffinose containing medium to mid-logarithmic phase. Cells were shifted to 37°C in pre-warmed 2% galactose containing medium for 3 hours. <i>B</i>, cells from <i>A</i> were quantified based on having only plasma membrane (PM) localization, only internal localization or both (vector n = 153, Sec14 n = 73, Sec14<sup>G266D</sup> n = 107) <i>C</i>, the wild type <i>SEC14</i> gene was replaced with the <i>sec14<sup>ts</sup></i> allele in a yeast strain expressing chimeric Pma1-RFP. The strain was transformed with either empty vector, a plasmid carried at low copy (ARS/CEN) containing wild type Sec14, and low and high copy (2 μ) plasmids containing Sec14<sup>G266D</sup>. Cells were grown at 25°C to mid-logarithmic phase and then transferred to 37°C for 16 hrs subsequent to determination Pma1-RFP localization by fluorescence microscopy.</p
The levels of Sec14<sup>G266D</sup> is regulated by the proteosome.
<p><i>A</i>, the level of Sec14 and Sec14<sup>G266D</sup> in <i>sec14<sup>ts</sup> rpn4</i>Δ cells. <i>B</i>, the level of Sec14 and Sec14<sup>G266D</sup> in <i>sec14<sup>ts</sup></i> cells treated with MG132. Strains were transformed with plasmids expressing Sec14 or Sec14<sup>G266D</sup> containing an N-terminal T7 epitope tag and were grown to mid-logarithmic phase at 25°C, with a subset shifted to 37°C for 2 hours (A). For MG132 treatment cells were grown as before and shifted to 37°C in the presence of 100 μM MG132 for 2 hours. Cells were disrupted by three passes through a French press and unbroken cells removed by centrifugation. Protein extract was separated by SDS-PAGE, transferred to PVDF membrane, and western blots versus the T7 epitope were performed. Pgk1 was used as load control.</p
Retinal vasculature development into the deep and intermediate layers of wild type and <i>Fzd4</i><sup>+/-</sup> mice under normoxic conditions.
Whole mount retinas of Fzd4+/+ and Fzd4+/- under normoxic conditions were stained with isolectin-594 and imaged at 25x magnification using a Zeiss LSM 510 Meta laser scanning confocal microscope. Z-stacks representing vascular growth in the deep and intermediate layers at the mid periphery were generated using 1 micron slices. Z-stacks were analyzed using the ImageJ software program. Green bars represent the X-axis, blue bars represent the Y-axis and purple represent the Z-axis. White arrows indicate examples of vessel branching in retinal layers.</p
Retinal vaso-obliteration of wild type and <i>Fzd4</i><sup>+/-</sup> mice after ocular ischemic retinopathy.
Wild type and Fzd4+/- mice were exposed to our OIR model from P7 to P12. (A) At P12 whole mounted retinas were stained with Alexa Fluor 594-conjugated GS-IB4 lectin and visualized using confocal microscopy (panel i). Vaso-obliterated areas are shown in white (panel ii). (B). Quantification of the vaso-obliterated area. Imaging analyses are expressed as mean ± standard error of the mean (SEM) and P values were calculated using a one-way ANOVA unpaired t-test. NS, not significant.</p
