Factors influencing player preferences for heroic roles in role-playing games.

Two studies were conducted to investigate whether player personality or social cognition influence preferences for heroic roles in role-playing games (RPG). In Study 1, 149 teenager subjects were categorized into five groups according to the Guilford Personality Inventory. Heroes were clustered into three types based on their attributes. The analysis of variance (ANOVA) results indicated that each personality group did not display distinctive preference for any particular heroic type. However, of the three heroic types teenagers most strongly preferred, Justice Warrior was followed, in order of preference, by Visionary Leader and Saint. In Study 2, the influence of three player social cognition factors (similarity, proximity, and familiarity) on player preference for heroic roles was studied. Multiple regression analysis results indicated that similarity and familiarity predicted player preferences for heroic roles.

Phosphorylation of mRNA decapping protein Dcp1a by the ERK signaling pathway during early differentiation of 3T3-L1 preadipocytes.

BACKGROUND: Turnover of mRNA is a critical step in the regulation of gene expression, and an important step in mRNA decay is removal of the 5' cap. We previously demonstrated that the expression of some immediate early gene mRNAs is controlled by RNA stability during early differentiation of 3T3-L1 preadipocytes. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that the mouse decapping protein Dcp1a is phosphorylated via the ERK signaling pathway during early differentiation of preadipocytes. Mass spectrometry analysis and site-directed mutagenesis combined with a kinase assay identified ERK pathway-mediated dual phosphorylation at Ser 315 and Ser 319 of Dcp1a. To understand the functional effects of Dcp1a phosphorylation, we examined protein-protein interactions between Dcp1a and other decapping components with co-immunoprecipitation. Dcp1a interacted with Ddx6 and Edc3 through its proline-rich C-terminal extension, whereas the conserved EVH1 (enabled vasodilator-stimulated protein homology 1) domain in the N terminus of Dcp1a showed a stronger interaction with Dcp2. Once ERK signaling was activated, the interaction between Dcp1a and Ddx6, Edc3, or Edc4 was not affected by Dcp1a phosphorylation. Phosphorylated Dcp1a did, however, enhanced interaction with Dcp2. Protein complexes immunoprecipitated with the recombinant phosphomimetic Dcp1a(S315D/S319D) mutant contained more Dcp2 than did those immunoprecipitated with the nonphosphorylated Dcp1a(S315A/S319A) mutant. In addition, Dcp1a associated with AU-rich element (ARE)-containing mRNAs such as MAPK phosphatase-1 (MKP-1), whose mRNA stability was analyzed under the overexpression of Dcp1a constructs in the Dcp1a knockdown 3T3-L1 cells. CONCLUSIONS/SIGNIFICANCE: Our findings suggest that ERK-phosphorylated Dcp1a enhances its interaction with the decapping enzyme Dcp2 during early differentiation of 3T3-L1 cells.