Complementation of snf1, a mutation affecting global regulation of carbon metabolism in yeast, by a plant protein kinase cDNA.

Abstract

A cDNA, cRKIN1, encoding a putative homologue of the yeast (Saccharomyces cerevisuiae) SNFl (6), human cells (7), and Xenopus (8) are also present in pea (9) and Arabidopsis (10). All protein kinases that have been characterized in detail contain a number of key residues and conserved regions in the catalytic domain (11) but can be divided into two classes: those that phosphorylate serine/threonine residues and those that phosphorylate tyrosine residues. In the present report, we present the nucleotide sequence of a cDNA, cRKIN1,** isolated from a rye endosperm cDNA library. The cRKIN1-encoded protein contains all the invariant residues and conserved domains characteristic ofeukaryotic protein-serine/threonine kinases. It is particularly similar to the product ofthe SNFJ gene of yeast (Saccharomyces cerevisiae) (12), a protein affecting global regulation of carbon metabolism, and the expression of cRKIN1 in yeast snfl mutants restores SNFJ function.

Immunological evidence that HMG‐CoA reductase kinase‐A is the cauliflower homologue of the RKIN1 subfamily of plant protein kinases

“…RK|N1 clearly represents the rye homologue of Snflp, since D'qA encoding RKIN1 rescues yeast snfl mutants, while RKIN1 and Snflp are 60% identical in sequence (within the kinase domain) at the amino acid level [13]. We regard these findings as important because, although at least 40 putative protein kinases have now been cloned from higher plants [23], the biochemical properties or physiological targets were not known for any of them, other than by analogy with animal or yeast homologues.…”

“…and SNF4 gene products, and is involved in yeast in the response to nutritional stress (starvation for glucose) [9][10][11][12]. A number of DNA sequences encoding proteins related to Snflp have been cloned from higher plants, including RKINI from rye [13], BKIN12 and BKIN2 from barley [14,15], AKINIO from A. thaliana [16], and NPK5 from tobacco [17]. These appear to be true homologues of SNFI, since RKIN1 or NPK5 DNAs rescue snJl disrupted mutants of S. cerevisiae in that they allow growth on nonfermentable carbon sources [13,17].…”

“…A number of DNA sequences encoding proteins related to Snflp have been cloned from higher plants, including RKINI from rye [13], BKIN12 and BKIN2 from barley [14,15], AKINIO from A. thaliana [16], and NPK5 from tobacco [17]. These appear to be true homologues of SNFI, since RKIN1 or NPK5 DNAs rescue snJl disrupted mutants of S. cerevisiae in that they allow growth on nonfermentable carbon sources [13,17]. However apart from this relationship with Snflp, nothing was known about the biochemical properties or function of the RKIN1 subfamily of plant protein kinases.…”

Similar substrate recognition motifs for mammalian AMP‐activated protein kinase, higher plant HMG‐CoA reductase kinase‐A, yeast SNF1, and mammalian calmodulin‐dependent protein kinase I

“…The specificity of SNF1 is, if anything, more stringent than that of AMPK, but whether this will be reflected in a more restricted specificity for physiological substrates remains to be determined. HRK-A is likely [2] to be the B. oleracea homologue of the product of the rye RKIN1 gene, which complements snfl mutations when expressed in yeast [25]. The similarities in specificity between the AMPK/SNF1 family and CaMKI were more surprising, and suggest that these kinases may share some physiological substrates.…”

The AMP-regulated kinase family: Enigmatic targets for diabetes therapy

“…First described 35 years ago (Beg et al, 1973;Carlson and Kim, 1973), and named in 1987 (Carling et al, 1987), mammalian AMPK is homologous to the yeast sucrose non-fermenting (Snf1) gene product, involved in substrate selection in S. cerevisiae (Celenza and Carlson, 1984), to the plant SNF-1 related kinase, SnRK (Alderson et al, 1991) and to C. elegans AAK-1 and AAK-2 (Apfeld et al, 2004). Considered principally as an "emergency response" enzyme in mammals, activated only during severe metabolic stress during which intracellular 5'AMP levels were raised as those of ATP fell, AMPK was substantially ignored by all but a very few groups for the next twenty years (Stapleton et al, 1996;Hardie et al, 1998).…”