Functional and phenotypic relevance of differentially expressed proteins in calcineurin mutants of Caenorhabditis elegans

Abstract

Calcineurin is a heterodimeric serine/threonine protein phosphatase, important for many cellular processes such as T-cell regulation, cardiac hypertrophy and kidney development. We previously reported the characterization of Caenorhabditis elegans calcineurin mutants as providing a simple but excellent genetic model system for studying in vivo functions of calcineurin. Calcineurin loss-of-function mutants, cnb-1(lf), and gain-of-function mutants, tax-6(gf), show certain opposite phenotypes as well as some similar phenotypes. In order to explain the phenotypic similarity observed in both loss-of-function and gain-of-function mutants, we examined the proteins that followed similar trends in both mutants relative to wild-type worms by using 2-DE. Interestingly, VHA-13, HSP-6 and phosphoenolpyruvate carboxykinase are down-regulated in both mutants. A total of 96 differentially regulated proteins were identified by MALDI-TOF/MS. Among these, 42 proteins are up-regulated and 54 proteins are down-regulated in calcineurin mutants. Furthermore, knock-down of about 30% of the genes, which are down-regulated in calcineurin mutants, showed some of the phenotypes of calcineurin-null mutants. This analysis suggests the functional relevance of these proteins to calcineurin activity in C. elegans.

Function and Evolution of a MicroRNA That Regulates a Ca2+-ATPase and Triggers the Formation of Phased Small Interfering RNAs in Tomato Reproductive Growth

“…There are prior examples where up-and downregulated expression of a gene can lead to a similar phenotype. These include the genes encoding BRI1-ASSOCI-ATED RECEPTOR KINASE1 (BAK1) in O. sativa (Wang et al, 2007a;Li et al, 2009), N-METHYL-D-ASPARTASE (NMDA), a subtype of Glu receptors, in animals (reviewed in Hardingham and Bading, 2003), and CALCINEURIN (CN) in Caenorhabditis elegans (Ahn et al, 2006). BAK1 is involved in brassinosteroid signaling, and plants exhibited a similar dwarf phenotype when BAK1 was upregulated or downregulated.…”

Caffeine Induces the Stress Response and Up-Regulates Heat Shock Proteins in Caenorhabditis elegans

“…Synchronized L1-stage worms were cultured in NGM containing 0 or 30 mM caffeine in a shaking incubator, and the total proteome was extracted and quantified as described previously ( Ahn et al, 2006 ). After quantification, 2-D gel electrophoresis; that is, isoelectric focusing (p I 3–10 or p I 4–7) and vertical sodium dodecyl sulfate gradient (7–13%) slab gel electrophoresis were performed as described previously ( Kawasaki et al, 2013 ).…”

Cholesterol-Responsive Metabolic Proteins Are Required for Larval Development in Caenorhabditis elegans

“…After growth in CN and CS for 48 h and 72 h, respectively, worms were harvested by washing the plates with M9 buffer and bacterial contamination was eliminated through centrifugation in 70% sucrose solution. Protein extraction and quantification were performed as previously described (Ahn et al, 2006).…”

“…Each IPG strip was equilibrated as previously described (Ahn et al, 2006). In the second dimension of electrophoresis, vertical sodium dodecyl sulfate gradient (7-13%) slab gel was used.…”