Molecular Control of Cell Function

Study Notes

Extracellular Signals

Cell surface receptors interact with ligands, like growth factors, to mediate signal transduction.
Communication among cells in multicellular organisms primarily occurs through extracellular signaling molecules and cell-cell contact.
Accommodation of cell responses often requires multiple extracellular signals for survival, growth, division, and differentiation.

Transcription Factors

Proteins that regulate gene expression, guiding the specification of different cell types and functions.
Early development relies on maternal transcription factors, while later stages are influenced by extracellular signals.

Induction Mechanism

Refers to the process where one cell population influences the development of neighboring cells, crucial for differentiation in tissues.

Cell Response Mechanism

Cells can adjust their sensitivity to signals through protein trafficking, phosphorylation, and ubiquitination processes.
Activation of receptor tyrosine kinases (RTKs) involves autophosphorylation and the binding of SH2 domain proteins.

Signalling Distance and Types

Extracellular signals can act over short or long distances, affecting cellular behavior depending on the signaling context.
There are three main types of cell-surface receptor proteins involved in signal transduction.

Intracellular Signaling Complexes

Forming at activated receptors allows for specific and precise signal relay in a crowded cytoplasm.
Response speed to signals is influenced by the turnover rate of signaling molecules, with mechanisms for positive and negative feedback.

Liquid-Liquid Phase Separation (LLPS)

LLPS is a phenomenon aiding in the organization of signaling complexes at the plasma membrane, allowing weak and transient protein interactions.
Upon activation, RTKs bind ligands, undergo autophosphorylation, and facilitate recruitment of signaling proteins, ultimately forming signaling droplets through LLPS.

Receptor Tyrosine Kinase (RTK) Dynamics

RTKs, such as FGF receptors, illustrate the process of receptor signaling and the role of phase separation in enhancing signal transduction and drug targeting.
The range of proteins involved in signaling cascades varies depending on the cell state and the ongoing signaling cascades.

Description

Explore the intricate molecular mechanisms that govern cell function and development. This quiz delves into the roles of extracellular signals, transcription factors, and the process of induction in cellular differentiation and response. Test your knowledge on how these components interact to influence developmental processes.