The Mek1 phosphorylation cascade plays a role in meiotic recombination of Schizosaccharomyces pombe.

Mek1 is a Chk2/Rad53/Cds1-related protein kinase that is required for proper meiotic progression of Schizosaccharomyces pombe. However, the molecular mechanisms of Mek1 regulation and Mek1 phosphorylation targets are unclear. Here, we report that Mek1 is phosphorylated at serine-12 (S12), S14 and threonine-15 (T15) by Rad3 (ATR) and/or Tel1 (ATM) kinases that are activated by meiotic programmed double-strand breaks (DSBs).

Spo5 phosphorylation is essential for its own timely degradation and for successful meiosis in Schizosaccharomyces pombe.

Protein phosphorylation is pivotal for meiotic progression, but little is known about its regulatory mechanisms. We show that before meiosis I, the meiosis-specific Schizosaccharomyces pombe protein Spo5 is phosphorylated in vivo on T29, T55, S59 and/or T63. In a mutant strain expressing Spo5 fused to green fluorescent protein with alanine substitutions of these amino acid sites (GFP; Spo5-4A-GFP), the timely degradation of Spo5 at meiosis II was not observed.

Mug27 is a meiosis-specific protein kinase that functions in fission yeast meiosis II and sporulation.

Several meiosis-specific proteins of Schizosaccharomyces pombe play essential roles in meiotic progression. We report here that a novel meiosis-specific protein kinase, Mug27 (also known as Ppk35), is required for proper spore formation. This kinase is expressed by the mug27(+) gene, which is abruptly transcribed after horsetail movement.

Meiosis specific coiled-coil proteins in Shizosaccharomyces pombe.

Many meiosis-specific proteins in Schizosaccharomyces pombe contain coiled-coil motifs which play essential roles for meiotic progression. For example, the coiled-coil motifs present in Meu13 and Mcp7 are required for their function as a putative recombinase cofactor complex during meiotic recombination. Mcp6/Hrs1 and Mcp5/Num1 control horsetail chromosome movement by astral microtubule organization and anchoring dynein respectively.

Mcp4, a meiotic coiled-coil protein, plays a role in F-actin positioning during Schizosaccharomyces pombe meiosis.

Some meiosis-specific proteins of Schizosaccharomyces pombe harbor coiled-coil motifs and play essential roles in meiotic progression. Here we describe Mcp4, a novel meiosis-specific protein whose expression is abruptly induced at the horsetail phase and which remains expressed until sporulation is finished. Fluorescence microscopic analysis revealed that Mcp4 alters its subcellular localization during meiosis in a manner that partially resembles the movement of F-actin during meiosis.