High impact information on Pknox1

• Hypomorphic mutation of the TALE gene Prep1 (pKnox1) causes a major reduction of Pbx and Meis proteins and a pleiotropic embryonic phenotype [1].
• Prep1 is also localized to FL endothelial progenitors, consistent with the observed angiogenic phenotype [1].
• Our data indicate that Prep1 is an essential gene that acts upstream of and within a Pbx-Meis network that regulates multiple aspects of embryonic development [1].
• To understand the in vivo role of Prep1, we have analyzed an embryonic lethal hypomorphic mutant mouse (Prep1(i/i)) [1].
• Furthermore, we have shown that the R2 motif functions as a strong PM site, with a high binding affinity for Prep1-Pbx1 dimers, and renamed this site R2/PM3 [2].

Biological context of Pknox1

• An additional 103 residues N-terminal to the Pbx dimerization interface restored heterodimerization with Hox and Meis1/Prep1 proteins [3].

Anatomical context of Pknox1

• Involvement of Prep1 in the alphabeta T-cell receptor T-lymphocytic potential of hematopoietic precursors [4].
• Immunocytochemical analysis demonstrated that PREP-1 was present in both granulosa cells and oocytes [5].
• The aim of the present study was to determine the expression of PBX and PREP-1 gene products in the mouse ovary and their localization to particular ovarian compartment, specifically the oocyte-containing ovarian follicle [5].
• In the adult mouse, PREP1 is expressed ubiquitously, with peaks in testis and thymus [6].

Associations of Pknox1 with chemical compounds

• Using glutathione S-transferase interaction assays, we demonstrate that Pbx1 and Prep1 interact with Smads 2 and 3 as well [7].
• No PREP-1 immunoreactivity was found in corpus luteum, theca or stroma [5].
• As with Hox proteins, a highly conserved tryptophan motif N-terminal to the DNA-binding domains of each myogenic bHLH family protein is required for cooperative DNA binding with Pbx-Meis1/Prep1 [8].

Other interactions of Pknox1

• We have identified a new PM site (PM2) and found that it cooperates with the R3 PH site to form ternary Prep1-Pbx1-Hoxb1 complexes [2].
• Therefore, the deficient postnatal T-lymphocytic potential of the Prep1 hematopoietic progenitors depends on the combined, not compensated, absence of Prep1 and at least Pbx2 [4].
• Segmental expression of Hoxb2 in r4 requires two separate sites that integrate cooperative interactions between Prep1, Pbx and Hox proteins [9].
• We describe Prep2, a new murine homeobox-containing gene closely related to Prep1 [10].

References