High impact information on ZIP1

• Analysis of zip1 mutants shows that Zip1 promotes dissociation of Dmc1 complexes [1].
• Dmc1 and, by inference, Rad51 form complexes before synapsis as monitored by immunostaining for Zip1 protein [1].
• The data presented show that the zip1 mutation does not affect chiasma function and confers only modest defects in meiotic recombination and sister chromatid cohesion [2].
• In the zip1 mutant, meiotic chromosomes fail to synapse, owing to the absence of a structural component of the synaptonemal complex (SC) [2].
• Immunofluorescence experiments using anti-ZIP1 antibodies demonstrate that the ZIP1 protein localizes to synapsed meiotic chromosomes but not to unsynapsed axial elements [3].

Biological context of ZIP1

• DMC1, RAD51, and ZIP1 encode two RecA homologs and a synaptonemal complex protein, respectively [4].
• Double labeling of wild-type meiotic chromosomes with anti-Zip1 and anti-Red1 antibodies demonstrates that Red1 localizes to chromosomes both before and during pachytene [5].
• With respect to the defect in interference and the level of crossing over, msh4 is similar to the zip1 mutant, which lacks a structural component of the synaptonemal complex (SC) [6].
• A PCH2-ZIP1-dependent checkpoint in meiosis is likely conserved among synaptic organisms from yeast to human [7].
• In a zip1 haploid, axial associations are not apparent, suggesting that these associations depend on interactions between homologous sequences [8].

Associations of ZIP1 with chemical compounds

• Zip1 is predicted to form an alpha-helical coiled coil, flanked by globular domains at the NH(2) and COOH termini [9].
• We discuss this regulation in S. cerevisiae and compare it with the regulation of two other transcriptional activators involved in cadmium detoxification: the Schizosaccharomyces pombe Zip1, regulated by SCF(Pof1), and the mammalian Nrf2, regulated by the SCF-like ubiquitin ligase Cul3:Rbx1:Keap1 [10].

Physical interactions of ZIP1

• Zip1 is a yeast synaptonemal complex (SC) central region component and is required for normal meiotic recombination and crossover interference [11].

Regulatory relationships of ZIP1

• Comparison of the expression of meiosis-specific Ndj1p-HA and Zip1p in haploid control and kar3Delta time courses revealed that fewer cells enter the meiotic cycle in absence of Kar3p [12].

Other interactions of ZIP1

• In yeast, mutations of this type include rad50S, dmc1, rad51, and zip1 [4].
• Crossing-over is decreased in the zip4 mutant (as in zip1, zip2, and zip3); the remaining crossovers are largely dependent on a parallel pathway utilizing Mms4. zip4 displays a novel phenotype: negative crossover interference, meaning that crossovers tend to cluster [13].
• Overproduction of either the meiotic chromosomal protein Red1 or the meiotic kinase Mek1 bypasses this checkpoint, allowing zip1 cells to sporulate [14].
• Physical analysis of meiotic recombination in a zip1 mutant reveals the following: Crossovers appear later than normal and at a reduced level [11].
• In the absence of DOT1, the zip1 and dmc1 mutants inappropriately progress through meiosis, generating inviable meiotic products [15].

Analytical, diagnostic and therapeutic context of ZIP1

• Our epitope mapping data indicate that the organization of Zip1 within polycomplexes is similar to that of the SC, whereas the organization of Zip1 within networks is fundamentally different [9].

References