Proteolysis

Proteolysis

Irreversible breaking of peptide bonds in proteins, essential for cell cycle and apoptosis

Proteases

Enzymes that hydrolyze peptide bonds, classified into metalloproteases, serine proteases, cysteine proteases, and aspartyl proteases

Zymogen

Inactive form of proteases synthesized to prevent damage, activated by specific cleavage sites

Metalloproteases

Proteases requiring metal ions for catalytic activity, involved in degrading extracellular matrix proteins and generating signaling molecules

ADAMs

A Disintegrin and Metalloproteinases, cleave membrane-associated proteins, regulate signaling pathways, and promote or inhibit signaling

MMPs

Matrix Metalloproteases targeting extracellular matrix proteins, involved in wound healing, ovulation, angiogenesis, and implicated in diseases like cancer and arthritis

PARs

Protease-activated receptors, activated by extracellular proteases like thrombin, crucial in cellular responses to vascular injury

Regulated Intramembrane Proteolysis (RIP)

Proteolytic processing within the membrane, essential for proteins like Notch ligands, amyloid precursor protein, and EGFR family member ErbB4

Ubiquitin

Small regulatory protein marking damaged proteins for destruction, essential for rapid changes in protein constituents in response to regulatory inputs

Proteasome

Molecular machine for degrading intracellular proteins, consisting of a cylindrical core and regulatory particles, involved in rapid degradation of cytosolic proteins

SCF Complex

E3 ubiquitin ligase complex regulating cell cycle progression by recognizing and marking phosphorylated target proteins for destruction

APC

Anaphase-promoting complex regulating cell cycle progression by triggering metaphase-to-anaphase transition and maintaining stable G1 phase

NF-κB

Transcription factor regulating genes involved in inflammation, immunity, cell proliferation, and apoptosis, activated by regulated degradation of inhibitory subunits

Caspases

Specialized proteases playing a central role in executing cell death program, regulated by inhibitor of apoptosis proteins (IAPs)

Bcl2 Family

Family of proteins determining cell fate by inducing or preventing mitochondrial outer membrane permeabilization, essential for intrinsic apoptotic pathway

Apoptosome

Multiprotein complex formed upon cytochrome c release, activating initiator caspase-9 and downstream signaling

Mitochondrial Release of Pro-Apoptotic Proteins

Process involving proteins like Smac/DIABLO, AIF, and EndoG, inducing cell death by disrupting energy generation or promoting apoptosis

True

The phosphorylation of a signaling protein by an upstreamkinase can represent a signaling input or output

Which of these is considered to be a currency for storing information?a. Localization of a signaling protein

b. Phosphorylation of a signaling protein

c. Conformational change of the protein

d. Covalent modification

e. All of the above

e. all of the above

Signaling pathways can be divided into events that occur mostly in .

a. Nucleus

b. Plasma membrane

c. Cytosol

d. A, B and C above

e. None of the above

d. A, B, and C above

Almost all proteases are activated by cleavage of an inactive precursor

True

Proteases exhibit preference for the amino acids that flank the bond to be cleaved

a. True

b. False

True

The process of breaking peptide bonds that form the backbone of proteins is called?

a. Localization

b. Necrosis

. Proteolysis

d. Phosphorylation

e. All of the above

Proteolysis

The principle of zymogen activation and signal amplification are illustrated in

a. Cell cycle regulation of vertebrates

b. Phosphorylation of vertebrates

c. Apoptosis of vertebrates

d. Blood coagulation of vertebrates

e. None of the above

d. blood coagulation of vertebrates