Cruciform DNA has been implicated in the initiation of DNA replication. Recently, we identified and purified from @entity1 (HeLa) cells a protein, @entity16221 , with binding specificity for cruciform DNA. We have reported previously that the @entity16221 activity sediments at approximately 66 kDa in a @entity653 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 @entity16221 reveals that it is 100% homologous to the 14-3-3 family of proteins and shows that @entity16221 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), @entity16221 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 @entity742 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.

XXXX cruciform binding protein belongs to the 14-3-3 family.

@entity1 :: ('9606', 'Species') :: ['human'] @entity742 :: ('9940', 'Species') :: ['sheep'] @entity653 :: ('MESH:D005990', 'Chemical') :: ['glycerol'] @entity16221 :: ('1387', 'Gene') :: ['CBP']
@entity1 :: (9606,Species) :: ['Human']
