Intracellular adenylate pools and protein degradation during zoosporangial differentiation in Allomyces arbuscula

Abstract

Ojha, M, and Turian, G, 1985, Intraceiiuiar adenylate pools and protein degradation during zoosporangial differentiation in AUomyces arbuscula. Piant, In Allomyees arbuscula Butl,, strain Bali, tiie ratio of protein to dry weight remained constant in exponentially growing but decreased in differentiating cultures, Tiie adenylate pools (ATP, ADP, AMP) and energy charge whicii integrates them, increased during zoospore germination and stabilized around 0,9 during differentiation, Tiie ievei of ATP increased early during tiie induction of zoosporangia for up to 1 ii and then declined. The ADP and AMP remained low for most of the time except for a transient increase in ADP (first 30 min induction). The energy charge was low in spores. The rate of turnover of proteins during growth and differentiation was more or Sess similar for up to i,5 h after transfer. Subsequently very little turnover of proteins occurred in the growing piants. In differentiating plants, the rate of degradation was maintained and by the end of the 4 ii experimental period 30% of the vegetative proteins were degraded. The intracellular ammonium siiowed a peak between 30 to 60 min of induction and was higher in the differentiating mycelia tiian in actively growing plants, while the giutamate pooi remained around 1 [xmol (mg protein)"' in both types of plants. The physiological role of these protein degradation products is discussed.Additional key words -Adenyiate nucieotide pools, intracellular ammonium kvels, protein dry weight ratios, M. Ojha (reprint requests) and G. Turian, Lab.