Dimensions of culture in intra-cultural comparisons: Individualism/collectivism and family-related values in three generations

The goal of the present study is to supplement inter-cultural comparison of values as a cultural dimension by intra-cultural comparisons, and to go beyond comparisons of single values representing cultural dimensions by studying value patterns on the individual level. Therefore, relationships among general (individualism, collectivism) and domain-specific (family- and child-related) values and the transmission of values in three generations of one family were analyzed. The sample consisted of 100 complete triads of three generations (grandmothers, mothers, and adolescents). The results showed that the individual value orientations of these three generations dif- fered in the expected direction. Individualistic values were more supported by the younger and less by the older generation. While individualism did not show significant relations to other specific values, collectivism was the most powerful dimension to predict family and child-related values. Individual- ism and collectivism clearly turned out as separate dimensions with different functions for the individual value system. The value structure of grandmoth- ers as compared to the younger generations showed more internal consistency. A relative transmission of values was obvious for the adjacent generations. The results are discussed from the perspective of cultural change and stability, and the relation among cultural dimensions and individual value orientations.

The changing values of children and preferences regarding family size in south Africa

This study extends the ongoing studies on values of children and intergenerational relations into an African context with the following key questions: To what extent can the structure of values of children (VOC) identified in previous studies be found in South Africa and what are women's preferences regarding the size of small, large, and ideal families? The sample consisted of three cohorts of Black South African women from the Limpopo Province. Factor analyses showed that the dimensions of VOC found in South Africa are a conglomeration of different values. Identified dimensions were Social/Emotional and Traditional/Utilitarian with respect to reasons for wanting children. Regarding reasons for not wanting children, Child as Source of Constraints and Constraints to Have a Child were identified. Intergenerational comparisons showed variations in the importance of value of children dimensions and in preferences regarding family size. Values of children of younger mothers were related to the number of children these women had and to their preferences regarding family size. The findings are discussed within the changing socio-political context of South Africa.

BPAG1a and b Associate with EB1 and EB3 and Modulate Vesicular Transport, Golgi Apparatus Structure, and Cell Migration in C2.7 Myoblasts.

BPAG1a and BPAG1b (BPAG1a/b) constitute two major isoforms encoded by the dystonin (Dst) gene and show homology with MACF1a and MACF1b. These proteins are members of the plakin family, giant multi-modular proteins able to connect the intermediate filament, microtubule and microfilament cytoskeletal networks with each other and to distinct cell membrane sites. They also serve as scaffolds for signaling proteins that modulate cytoskeletal dynamics. To gain better insights into the functions of BPAG1a/b, we further characterized their C-terminal region important for their interaction with microtubules and assessed the role of these isoforms in the cytoskeletal organization of C2.7 myoblast cells. Our results show that alternative splicing does not only occur at the 5' end of Dst and Macf1 pre-mRNAs, as previously reported, but also at their 3' end, resulting in expression of additional four mRNA variants of BPAG1 and MACF1. These isoform-specific C-tails were able to bundle microtubules and bound to both EB1 and EB3, two microtubule plus end proteins. In the C2.7 cell line, knockdown of BPAG1a/b had no major effect on the organization of the microtubule and microfilament networks, but negatively affected endocytosis and maintenance of the Golgi apparatus structure, which became dispersed. Finally, knockdown of BPAG1a/b caused a specific decrease in the directness of cell migration, but did not impair initial cell adhesion. These data provide novel insights into the complexity of alternative splicing of Dst pre-mRNAs and into the role of BPAG1a/b in vesicular transport, Golgi apparatus structure as well as in migration in C2.7 myoblasts.

Interaction of Plectin with Keratins 5 and 14: Dependence on Several Plectin Domains and Keratin Quaternary Structure.

Plectin, a cytolinker of the plakin family, anchors the intermediate filament (IF) network formed by keratins 5 and 14 (K5/K14) to hemidesmosomes, junctional adhesion complexes in basal keratinocytes. Genetic alterations of these proteins cause epidermolysis bullosa simplex (EBS) characterized by disturbed cytoarchitecture and cell fragility. The mechanisms through which mutations located after the documented plectin IF-binding site, composed of the plakin-repeat domain (PRD) B5 and the linker, as well as mutations in K5 or K14, lead to EBS remain unclear. We investigated the interaction of plectin C terminus, encompassing four domains, the PRD B5, the linker, the PRD C, and the C extremity, with K5/K14 using different approaches, including a rapid and sensitive fluorescent protein-binding assay, based on enhanced green fluorescent protein-tagged proteins (FluoBACE). Our results demonstrate that all four plectin C-terminal domains contribute to its association with K5/K14 and act synergistically to ensure efficient IF binding. The plectin C terminus predominantly interacted with the K5/K14 coil 1 domain and bound more extensively to K5/K14 filaments compared with monomeric keratins or IF assembly intermediates. These findings indicate a multimodular association of plectin with K5/K14 filaments and give insights into the molecular basis of EBS associated with pathogenic mutations in plectin, K5, or K14 genes.Journal of Investigative Dermatology advance online publication, 10 July 2014; doi:10.1038/jid.2014.255.

Evolution of the spermadhesin gene family

Spermadhesins belong to a novel family of secretory proteins of the male genital tract. They are major proteins of the seminal plasma and have been found peripherally associated to the sperm surface. So far, they have only been detected in ungulates, specifically in pig, cattle, and horse, respectively. Spermadhesins form a subgroup of the superfamily of proteins with a CUB-domain that has been found in a variety of developmentally regulated proteins. The structure and function of the spermadhesins have been investigated in the pig. They are multifunctional proteins showing a range of ligand-binding abilities, e.g. to carbohydrates, phospholipids, and protease inhibitors, suggesting that they may be involved in different steps of fertilization. We report here the genomic organization of the porcine spermadhesin gene cluster as well as a detailed comparative analysis with respect to other mammalian species. The porcine spermadhesin genes are located on SSC 14q28-q29 in a region syntenic to HSA 10q26. The pig contains five closely linked spermadhesin genes, whereas only two spermadhesin genes are present in the cattle genome. Inactive copies of spermadhesin genes are still detectable in the human, chimp, and dog genome while the corresponding region was lost from the rodent genomes of mouse and rat. Within the pig, the five spermadhesin genes contain both highly diverged and highly conserved regions. Interestingly, the pattern of divergence does not correlate with the position of the exons. Evolutionary analyses suggest that the pattern of diversity is shaped by ancestral variation, recombination, and new mutations.

Cryo-EM structure of aerolysin variants reveals a novel protein fold and the pore-formation process

Owing to their pathogenical role and unique ability to exist both as soluble proteins and transmembrane complexes, pore-forming toxins (PFTs) have been a focus of microbiologists and structural biologists for decades. PFTs are generally secreted as water-soluble monomers and subsequently bind the membrane of target cells. Then, they assemble into circular oligomers, which undergo conformational changes that allow membrane insertion leading to pore formation and potentially cell death. Aerolysin, produced by the human pathogen Aeromonas hydrophila, is the founding member of a major PFT family found throughout all kingdoms of life. We report cryo-electron microscopy structures of three conformational intermediates and of the final aerolysin pore, jointly providing insight into the conformational changes that allow pore formation. Moreover, the structures reveal a protein fold consisting of two concentric β-barrels, tightly kept together by hydrophobic interactions. This fold suggests a basis for the prion-like ultrastability of aerolysin pore and its stoichiometry.