Cruciform DNA has been implicated in the initiation of DNA replication. Recently, we identified and purified from human (HeLa) cells a protein, CBP, with binding specificity for cruciform DNA. We have reported previously that the CBP activity sediments at approximately 66 kDa in a glycerol gradient. Here, photochemical cross-linking studies and Southwestern analyses confirm that a 70 kDa polypeptide interacts specifically with cruciform DNA. Microsequence analysis of tryptic peptides of the 70 kDa CBP reveals that it is 100% homologous to the 14-3-3 family of proteins and shows that CBP contains the epsilon, beta, gamma, and zeta isoforms of the 14-3-3 family. In addition to polypeptides with the characteristic molecular mass of 14-3-3 proteins (30 and 33 kDa), CBP also contains a polypeptide of 35 kDa which is recognized by an antibody specific for the epsilon isoform of 14-3-3. Cruciform-specific binding activity is also detected in 14-3-3 proteins purified from sheep brain. Immunofluorescene studies confirm the presence of the epsilon, beta, and zeta isoforms of 14-3-3 proteins in the nuclei of HeLa cells. The 14-3-3 family of proteins has been implicated in cell cycle control, and members of this family have been shown to interact with various signaling proteins. Cruciform binding is a new activity associated with the 14-3-3 family.

We have generated a panel of deletion mutants of ors8 (483 bp), a mammalian autonomously replicating DNA sequence, previously isolated by extrusion of nascent monkey (CV-1) DNA from replication bubbles active at the onset of S phase. The deletion mutants were tested for replication function by the DpnI resistance assay, in vivo, after transfection into HeLa cells, and in vitro. An internal fragment of 186-bp that is required for autonomous replication function of ors8 was identified. This fragment, when subcloned into pBR322 and similarly tested, was capable of autonomous replication in vivo and in vitro. The 186-bp fragment contains several repeated sequence motifs, such as the ATTA and ATTTAT motifs, occurring three and five times, respectively, the sequences TAGG and TAGA, occurring three and seven times, respectively, two 5'-ATT-3' repeats, a 44-bp imperfect inverted repeat (IR) sequence, and an imperfect consensus binding element for the transcription factor Oct-1. A measurable sequence-directed DNA curvature was also detected, coinciding with the AT-rich regions of the 186-bp fragment.

This paper analyses the findings of a two-stage small-scale research project investigating the needs of undergraduate students with dependent children (‘student-parents’) studying in a post-1992 university. The findings of Stage 1 of the study, using data from semi-structured interviews with student-parents, show that student-parents need two things from their institution: a sense of belonging and flexibility. In Stage 2, a questionnaire survey was used to explore the impact of two interventions piloted during the 2021-22 academic year to address the Stage 1 findings. The paper then presents the next steps in this project: co-creation, with students, of systems designed not only to make visible our student-parent community but also to support, empower and celebrate their identities as student-parents.

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