Purification and Partial Characterization of a Factor, a Mating Hormone Produced by Mating‐Type‐a Cells from Saccharomyces cerevisiae

Publisher Website
Google Scholar
Abstract
Cells of S. cerevisiae exhibiting the a mating type secrete into the culture medium a mating-type-specific hormone activity (a factor), which specifically causes a transient arrest of DNA replication and cell division in cells of the opposite mating type, .alpha.. Three compounds exhibiting a factor activity were found in culture filtrates from a cells. The most active compound was purified more than 105-fold and appears to be homogeneous on the basis of TLC and thin-layer electrophoresis in different systems. Possibly this compound, which exhibits in .alpha. cells the biological activities that were attributed to a factor, represents pure a factor. a Factor was characterized as a very hydrophobic undecapeptide with the following amino acid composition: H2N-Tyr(Asx1, Gly1, Ala1, Val1, Ile2, Phe1, Lys1, Trp1, Pro1). Although in their respective target cells the biological effects of a factor and of .alpha. factor, the corresponding mating hormone of mating-type-.alpha. cells, are remarkably similar, the primary structures of both hormones appear quite different.