High impact information on tk1a-A

• This constitutes a simplified system with which to study the signal transduction pathway from the DNA template to the tyrosine kinase responsible for inhibiting p34cdc2 activity [1].
• Furthermore, we have shown that low levels of M13 single-stranded DNA and high levels of double-stranded plasmid DNA can elevate the tyrosine kinase activity responsible for phosphorylating p34cdc2, thereby inactivating maturation-promoting factor and inhibiting entry into mitosis [1].
• This is the first demonstration that a tyrosine kinase oncogene product, p65tpr-met, can induce meiotic maturation in Xenopus oocytes and activate MPF through a mos-dependent pathway, possibly the insulin or insulinlike growth factor 1 pathway [2].
• tpr-met, a tyrosine kinase oncogene, is the activated form of the met proto-oncogene that encodes the receptor for hepatocyte growth factor/scatter factor [2].
• The Xenopus annexin II heavy chain lacks the highly conserved tyrosine at position 23 which is the site of src oncogene tyrosine kinase phosphorylation in the murine protein [3].

Biological context of tk1a-A

• Recent data demonstrate that metabolism of inositol 1,4,5-trisphosphate (IP(3)), a second messenger for Ca(2+) release, is carefully regulated and involves phospholipase C (PLC) and the tyrosine kinase Src [4].
• In conclusion, a multigene family (ERK) encoding protein kinases that have the capacity to convert tyrosine kinase signals to serine/threonine phosphorylation signals has been identified in animal and yeast cells [5].
• By using this experimental system, we have reconstituted a series of signal transduction events associated with egg fertilization, such as sperm-egg membrane interaction, activation of Src tyrosine kinase and phospholipase Cgamma, production of inositol trisphosphate, transient calcium release, and cell cycle transition [6].

Anatomical context of tk1a-A

• To determine whether increases in tyrosine kinase activity are part of this pathway, we microinjected tyrosine kinase inhibitors into unfertilized eggs [7].
• Four different ligand-receptor binding pairs of the GDNF (glial cell line-derived neurotrophic factor) family exist in mammals, and they all signal via the transmembrane RET receptor tyrosine kinase [8].

Associations of tk1a-A with chemical compounds

• The recorded current was independent of extracellular Ca2+ but involved tyrosine kinase phosphorylation and intracellular Ins(1,4,5)P3 sensitive stores [9].
• Thus we provide evidence for clear differences in the signalling pathways that control glucose transport by G-protein-coupled and tyrosine kinase growth-factor receptors [10].
• The tyrosine kinase inhibitor genistein alone activated a small chloride current in whole oocytes expressing CFTR and substantially increased the chloride current obtained upon stimulation with forskolin and isobutyl methylxanthine (IBMX) [11].
• We also show that the caffeine-induced activation of the p34cdc2 protein kinase is not mediated by either of the two second messengers, calcium and cAMP, or by inhibition of the p34cdc2 tyrosine kinase [12].

Other interactions of tk1a-A

• Our results suggest that the activation of PKC and tyrosine kinase but not actin reorganization plays a role in the SSC potentiating action of fibronectin [13].

Analytical, diagnostic and therapeutic context of tk1a-A

• Since this inhibition of egg activation by tyrosine kinase inhibitors can be overcome by Ca2+ microinjection, the inhibitors must act on a step in the signal transduction cascade that is upstream of the Ca2+ wave [7].

References