Disease relevance of RPS6KA1

• Amino acids 44-733 of S6KII alpha were expressed in Escherichia coli and the recombinant protein was used to raise antiserum in rabbits [1].
• In addition, anti-S6 K II serum reacted with activated S6 kinase from chicken embryo fibroblasts stimulated with serum or transformed by Rous sarcoma virus [2].
• An S6 kinase clone, closely related to S6 kinase II, was subsequently identified and the protein product was expressed in a baculovirus system [3].

High impact information on RPS6KA1

• Incubation of MAP2 kinase from insulin-treated 3T3-L1 adipocytes with phosphatase-inactivated S6 kinase II from Xenopus leads to partial reactivation and phosphorylation of the enzyme [4].
• Comparison of complementary DNA sequences shows that this enzyme is distinct from S6 kinase II (92K) found in Xenopus eggs and fibroblasts [4].
• Immunocomplexes formed with the antiserum and purified S6 K II were able to express kinase activity with the same substrate specificity as that of the purified enzyme, including autophosphorylation of S6 K II itself [2].
• Immunocomplex kinase assays done on extracts revealed that anti-S6 K II serum reacted with S6 kinase from progesterone-treated oocytes [2].
• An insulin-stimulated phosphorylation cascade was examined in rat liver after insulin injection via a portal vein by the use of immune complex kinase assays specific to the mitogen-activated protein (MAP) kinase and S6 kinase II homologue (rsk) kinase [5].

Biological context of RPS6KA1

• The changes in NEP-B during metaphase did not appear to be regulated directly by either p34cdc2/cyclin B, S6 kinase II or MAP kinase [6].
• However, it clearly differs from S6 kinase II in that it has only one, rather than two predicted catalytic domains and a deduced molecular mass of 59,109 Da [7].

Anatomical context of RPS6KA1

• Purification and characterisation of the insulin-stimulated protein kinase from rabbit skeletal muscle; close similarity to S6 kinase II [8].

Associations of RPS6KA1 with chemical compounds

• Phosphoamino acid analysis of S6 kinase II labeled in vivo during maturation reveals both phosphoserine and phosphothreonine, and phosphopeptide maps suggest that several kinases may phosphorylate and activate S6 kinase II in vivo [9].
• The activation of MPF, MAP kinase and S6 kinase II by PKC zeta was sensitive to cycloheximide, while induction of GVBD was independent of protein synthesis [10].
• The ISPK comigrated during SDS/polyacrylamide gel electrophoresis with the enzyme S6 kinase II from Xenopus eggs, and was recognised in immunoblotting and immunoprecipitation experiments by antibodies raised against S6 kinase II [8].

Other interactions of RPS6KA1

• Previous studies have shown that increased ribosomal protein S6 kinase activity in unfertilized Xenopus eggs can be resolved by DEAE-Sephacel chromatography into two peaks, designated S6 kinase I and S6 kinase II [9].

Analytical, diagnostic and therapeutic context of RPS6KA1

• We report the molecular cloning of cDNAs for S6 kinase II (S6KII) mRNAs present in Xenopus ovarian tissue [1].
• Microinjection of PKC zeta induced the early activation of MPF which precedes GVBD and also induced the activation of MAP kinase and S6 kinase II [10].

References