Regulation of OPA1-mediated mitochondrial fusion by leucine zipper/EF-hand-containing transmembrane protein-1 plays a role in apoptosis

Carboxyl-terminal modulator protein (CTMP) is a tumor suppressor-like binding partner of Protein kinase B (PKB/Akt) that negative regulates this kinase. In the course of our recent work, we identified that CTMP is consistently associated with leucine zipper/EF-hand-containing transmembrane-1 (LETM1). Here, we report that adenovirus-LETM1 increased the sensitivity of HeLa cells to apoptosis, induced by either staurosporine or actinomycin D. As shown previously, LETM1 localized to the inner mitochondrial membrane. Electron-microscopy analysis of adenovirus-LETM1 transduced cells revealed that mitochondrial cristae were swollen in these cells, a phenotype similar to that observed in optic atrophy type-1 (OPA1)-ablated cells. OPA1 cleavage was increased in LETM1-overexpressing cells, and this phenotype was reversed by overexpression of OPA1 variant-7, a cleavage resistant form of OPA1. Taken together, these data suggest that LETM1 is a novel binding partner for CTMP that may play an important role in mitochondrial fragmentation via OPA1-cleavage

Humane orientation, work–family conflict, and positive spillover across cultures

Although cross-national work–family research has made great strides in recent decades, knowledge accumulation on the impact of culture on the work–family interface has been hampered by a limited geographical and cultural scope that has excluded countries where cultural expectations regarding work, family, and support may differ. We advance this literature by investigating work–family relationships in a broad range of cultures, including understudied regions of the world (i.e., Sub-Saharan Africa, Southern Asia). We focus on humane orientation (HO), an overlooked cultural dimension that is however central to the study of social support and higher in those regions. We explore its moderating effect on relationships between work and family social support, work–family conflict, and work–family positive spillover. Building on the congruence and compensation perspectives of fit theory, we test alternative hypotheses on a sample of 10,307 participants from 30 countries/territories. We find HO has mostly a compensatory role in the relationships between workplace support and work-to-family conflict. Specifically, supervisor and coworker supports were most strongly and negatively related to conflict in cultures in which support is most needed (i.e., lower HO cultures). Regarding positive spillover, HO has mostly an amplifying role. Coworker (but not supervisor) support was most strongly and positively related to work-to-family positive spillover in higher HO cultures, where providing social support at work is consistent with the societal practice of providing support to one another. Likewise, instrumental (but not emotional) family support was most strongly and positively related to family-to-work positive spillover in higher HO cultures