Disease relevance of byr1

• Furthermore, we have found that byr1 is allelic to ste1, one of at least 10 genes which when mutated can cause sterility [1].

High impact information on byr1

• When coexpressed with Raf kinase, however, MAP kinase kinase is activated by phosphorylation and the mating defect of the byr1 mutant is rescued [2].
• Purification of a murine protein-tyrosine/threonine kinase that phosphorylates and activates the Erk-1 gene product: relationship to the fission yeast byr1 gene product [3].
• Furthermore, this phosphorylation was diminished in a byr1 disruptant strain, suggesting that spk1 lies downstream of byr1, which encodes a MAPKK homolog in S. pombe [4].
• Schizosaccharomyces pombe ras1 and byr1 are functionally related genes of the ste family that affect starvation-induced transcription of mating-type genes [1].
• MAPKK (393 residues, Mr 43,330) is a new member of the protein kinase subclass that comprises byr1 and STE7 that are involved in pheromone dependent signal transduction in yeast, wis1 a mitotic regulator in S. pombe and PBS2, which confers antibiotic resistance in S. cerevisiae [5].

Biological context of byr1

• These observations provide a molecular basis for the role of the ste gene family, including ras1 and byr1, in meiosis and indicate that further characterization of other ste genes would be very useful for elucidating the mechanism of ras1 function in fission yeast cells [1].
• Both two dominant mutants bypassed the inability to make spores in ras1 deficient diploid cells, suppressed the deficiency to execute sporulation in byr2 deficient diploid cells, but failed to suppress the byr1 deficiency [6].
• No sexual activities were detected in ste11 strains (previously referred to as aff1 or steX, which we show are allelic), whilst the production of M factor was unaffected by ste1 to ste10 mutations [7].
• We present evidence that ste 1.1 is defective in the production of a non-diffusible and non-mating-type specific factor. ste 1 and cdc 25 both map on chromosome I and are loosely linked [8].

Other interactions of byr1

• Several physiological similarities between strains containing null alleles of these genes supports the idea that ras1 and byr1 are functionally closely related [1].

References