Kinases Flashcards
What are kinases?
Kinases are enzymes that transfer phosphate groups from ATP to specific substrates, playing a crucial role in cellular signaling.
How are kinases activated?
Kinases are often activated through phosphorylation of the activation loop or by binding regulatory proteins, altering their structure to activate them.
How do kinases recognize specific substrates?
How do kinases recognize specific substrates?
What are the main types of kinases?
Kinases are classified into serine/threonine kinases and tyrosine kinases based on the amino acids they phosphorylate.
What families do kinases belong to?
Kinase families include the AGC, CAMK, and CMGC families, which group kinases with similar structures and functions.
What mechanisms regulate kinases?
Kinases are regulated by phosphorylation, binding of regulatory proteins, and cellular localization.
How is structural biology used in studying kinases?
Techniques such as X-ray crystallography and NMR spectroscopy are used to study kinase structures.
What is a kinase assay?
Kinase assays measure kinase activity and screen for inhibitors using techniques like radioactive, fluorescent, and mass spectrometry-based assays.
What are kinase inhibitors and their use?
Kinase inhibitors block kinase activity and are used as therapeutic agents in diseases like cancer.
What roles do kinases play in diseases?
Kinases are implicated in diseases like diabetes and neurodegenerative diseases, and mutations in kinases can lead to various diseases.
What is allosteric regulation of kinases?
Allosteric regulation involves molecules binding at sites other than the active site to modulate kinase activity.
How are PKCs classified?
PKCs are classified into classic (require calcium), novel (activated by DAG), and atypical (do not require calcium or DAG) groups.
What is Protein Kinase C (PKC)?
PKC is a family of enzymes that phosphorylate serine and threonine residues on target proteins, playing critical roles in several cellular processes.
How are PKCs activated?
PKCs are activated by binding specific cofactors that induce conformational changes, relieving autoinhibition by the regulatory domain.
What is the role of the pseudosubstrate segment in PKCs?
The pseudosubstrate segment keeps PKCs inactive by blocking the catalytic site, mimicking the actual substrate without being phosphorylated.
What domains do PKCs have?
PKCs have an N-terminal regulatory domain and a C-terminal catalytic domain.
How does Protein Kinase A (PKA) get activated?
PKA is activated by cAMP binding to its regulatory subunits, releasing and activating the catalytic subunits.
How does muscle contraction affect phosphorylase kinase?
Muscle contraction increases Ca²⁺ levels, directly activating phosphorylase kinase, which then activates glycogen phosphorylase to break down glycogen for energy.
What is the structure of Src kinases?
Src kinases have SH3, SH2, and kinase domains, along with a regulatory tail that controls their activity.
How are Src kinases activated?
Src kinases are activated by dephosphorylation of Tyr527 and binding of SH2 and SH3 domains to target proteins, inducing conformational changes.
What functions do Src kinases have?
Src kinases regulate cell growth, survival, adhesion, migration, differentiation, and immune responses.
What are tyrosine kinase inhibitors and their role in CML?
Tyrosine kinase inhibitors, like Gleevec, target abnormal kinase activity in CML by blocking the ATP-binding site of the BCR-ABL fusion protein.
What types of signal transduction exist?
Signal transduction can be intercellular (communication between cells) or intracellular (signal processing within a cell).
What mechanisms regulate gene expression?
Gene expression is regulated through protein-DNA interactions, transcription regulation, and posttranscriptional processes.
