WHI-2 Regulates Intercellular Communication via a MAP Kinase Signaling Complex.
A Pedro Gonçalves1, Karen M Chow1, Sara Cea-Sánchez2
1Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States.
Frontiers in Microbiology
|February 11, 2020
Summary
WHI-2 protein is crucial for fungal cell fusion and communication in Neurospora crassa. It regulates endocytosis and signaling pathways essential for forming mycelial networks.
Area of Science:
- Mycology
- Cell Biology
- Genetics
Background:
- Fungal mycelial network formation relies on somatic cell fusion of germinating spores.
- Chemotropic growth in Neurospora crassa germlings involves mitogen-activated protein kinase (MAPK) signaling cascades.
- Mutations in Δwhi-2, Δcsp-6, and Δamph-1 disrupt cell fusion and communication.
Purpose of the Study:
- To investigate the function of WHI-2 in fungal cell fusion and signaling.
- To elucidate the roles of CSP-6 and AMPH-1 in these processes.
- To understand the molecular mechanisms underlying chemotropic interactions and cell fusion in Neurospora crassa.
Main Methods:
- Localization studies of WHI-2.
- Analysis of mutant phenotypes (Δwhi-2, Δcsp-6, Δamph-1).
- Investigation of MAPK pathway signaling and transcription factor targeting.
Main Results:
- WHI-2 localizes to the cell periphery and is vital for endocytosis, mitochondrial organization, sporulation, and cell fusion.
- WHI-2 mediates signal transduction through the NRC-1/MEK-2/MAK-2 MAPK pathway.
- Δamph-1 mutants' deficiencies were rescued by WHI-2 mis-expression, and CSP-6 activity is essential for fusion.
Conclusions:
- WHI-2 plays a multifaceted role in fungal development, including regulating endocytosis and MAPK signaling.
- The study identifies WHI-2, CSP-6, and AMPH-1 as key genetic components in Neurospora crassa cell fusion.
- WHI-2's role in endocytosis may be critical for signal perception during chemotropic interactions.
Related Concept Videos
01:07MAPK Signaling Cascades
7.7K
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
7.7K
01:19Interactions Between Signaling Pathways
7.1K
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
7.1K
01:16Calmodulin-dependent Signaling
5.9K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.9K
01:15Amplifying Signals via Second Messengers
8.2K
Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be relayed by second messengers present in the cell cytoplasm. There are several second messenger pathways, each with its own way of relaying information. For example, the G protein-coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol pathway is active when the receptor induces...
8.2K
01:20The JAK-STAT Signaling Pathway
11.6K
Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as SH2...
11.6K
01:30Assembly of Signaling Complexes
6.4K
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
6.4K