Sn Rk 202 14 2002

Abstract Sucrose nonfermenting-1 (SNF1)-related protein kinases (SnRKs) form a major family of signalling proteins in plants and have been associated with metabolic regulation and stress responses. They comprise three subfamilies: SnRK1, SnRK2, and SnRK3. SnRK1 plays a major role in the regulation of carbon metabolism and energy status, while SnRKs 2 and 3 have been implicated in stress and abscisic acid (ABA)-mediated signalling pathways. The burgeoning and divergence of this family of protein kinases in plants may have occurred to enable cross-talk between metabolic and stress signalling, and ABA-response-element-binding proteins (AREBPs), a family of transcription factors, have been shown to be substrates for members of all three subfamilies. In this study, levels of SnRK1 protein were shown to decline dramatically in wheat roots in response to ABA treatment, although the amount of phosphorylated (active) SnRK1 remained constant. Multiple SnRK2-type protein kinases were detectable in the root extracts and showed differential responses to ABA treatment. They included a 42 kDa protein that appeared to reduce in response to 3 h of ABA treatment but to recover after longer treatment.

There was a clear increase in phosphorylation of this SnRK2 in response to the ABA treatment. Fractions containing this 42 kDa SnRK2 were shown to phosphorylate synthetic peptides with amino acid sequences based on those of conserved phosphorylation sites in AREBPs. The activity increased 8-fold with the addition of calcium chloride, indicating that it is calcium-dependent. The activity assigned to the 42 kDa SnRK2 also phosphorylated a heterologously expressed wheat AREBP.

Breakin' 2 electric boogaloo cast. FALCON 900B, SN 1. The Dassault Falcon 900B is a comfortable three-engine, long-range business jet, with international capabilities, and up to 3,950 nm range. It is known for its excellent handling characteristics and fuel efficiency, as well as its ability to operate from short runways. Purcell PC, Smith AM, Halford NG (1998) Antisense expression of a sucrose non-fermenting-1-related protein kinase sequence in potato results in decreased expression of sucrose synthase in tubers and loss of sucrose-inducibility of sucrose synthase transcripts in leaves. Plant J 14:195–202 CrossRef Google Scholar.

,,, Introduction Sucrose nonfermenting-1 (SNF1)-related protein kinases (SnRKs) form a major family of signalling proteins in plants and have been associated with metabolic regulation and stress responses (; ). SnRKs have been grouped into three subfamilies: SnRK1, SnRK2, and SnRK3 (). SnRK1, the homologue of adenosine monophosphate-activated protein kinase (AMPK) from mammals and SNF1 from yeast, has been implicated in the regulation of carbon metabolism and energy status (; ). It controls metabolism at multiple levels; for example, it phosphorylates enzymes such as 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) and sucrose phosphate synthase, leading to their inactivation.