The Eukaryotic Cell Cycle and Regulation

These flashcards cover key concepts from the lecture on the Eukaryotic Cell Cycle, its regulation, and associated mechanisms.

Eukaryotic Cell Cycle

A highly regulated ordered series of events that cells go through as they grow and divide.

Homologous chromosomes

Pairs of chromosomes consisting of one chromosome from each parent that are similar in shape, size, and genetic content.

S phase

The phase of the cell cycle in which DNA replication occurs.

CDK (Cyclin-Dependent Kinase)

A type of enzyme that, when combined with a cyclin, regulates the cell cycle by phosphorylating target proteins.

Cyclin

A family of proteins that regulate the cell cycle by activating CDKs and controlling progression through the cycle.

Cell Cycle Checkpoints

Mechanisms in the cell cycle that monitor and regulate progression through various phases to prevent errors.

MPF (Maturation Promoting Factor)

A cyclin-CDK complex that triggers the transition from G2 into M-phase (mitosis).

Apoptosis

A process of programmed cell death that occurs in multicellular organisms, often in response to cellular damage.

Sic1

An inhibitor protein in yeast that prevents premature entry into S phase by inhibiting S phase CDKs.

p53

A tumor suppressor protein that regulates the cell cycle and functions as a transcription factor to induce cell cycle arrest in response to DNA damage.

Anaphase Promoting Complex (APC)

A protein complex that triggers the separation of sister chromatids during anaphase of mitosis by degrading the anaphase inhibitor.

G1 Phase

The first phase of the cell cycle during which the cell grows and prepares for DNA replication.

Mitosis

The phase of the cell cycle in which a eukaryotic cell divides its nucleus and genetic material, followed by cell division (cytokinesis).

Genetic Mutations

Alterations in DNA sequence that can lead to changes in gene function and may contribute to diseases like cancer.

Temperature-sensitive mutations

Mutations that prevent growth at high temperatures but allow growth at lower (permissive) temperatures.

Cdc mutants

Cell division cycle mutants that disrupt the normal cell cycle progression.

Yeast Models

Utilization of budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) for studying cell cycle regulation.

Diffusible Factors

Soluble molecules that can alter the behavior of neighboring cells, influencing cell cycle entry and progression.

Checkpoint Genes

Genes that code for proteins enforcing checkpoints during the cell cycle to prevent progression in case of errors.

Protein Degradation

The process through which proteins are broken down, playing a crucial role in regulating the cell cycle and preventing errors.

Kinase

An enzyme that catalyzes the transfer of phosphate groups to specific substrates, often involved in signaling pathways.

Phosphatase

An enzyme that removes phosphate groups from proteins, often reversing the action of kinases and regulating cell cycle progression.

G2 Phase

The second gap phase of the cell cycle after DNA synthesis, where the cell prepares for mitosis.

The Cohesin Complex

Protein complexes responsible for holding sister chromatids together before separation during anaphase.

Mad2

Spindle-assembly checkpoint: Inhibits APC-cdc20 until amphitelic capture of all chromosomes

cdc14

Chromosome-segregation checkpoint. It is inhibited until chromosomes segregate. It activates APC-Cdh1 to destroy MPF and Sic1 to inhibit MPF.