Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Complement System01:27

Complement System

1.9K
The complement system is a group of approximately 20 plasma proteins that strengthen the body's defenses against infections through opsonization, inflammation, and cell lysis. Opsonization involves coating pathogens with complement proteins, making them more recognizable and facilitating phagocyte engulfment. Certain complement proteins induce inflammation that attracts immune cells to the site of infection. Cell lysis involves the destruction of pathogens through the formation of a...
1.9K
IP3/DAG Signaling Pathway01:11

IP3/DAG Signaling Pathway

11.6K
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the  phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
11.6K
Intracellular Signaling Cascades01:24

Intracellular Signaling Cascades

46.0K
Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the...
46.0K
What are Second Messengers?01:12

What are Second Messengers?

81.8K
Because many receptor binding ligands are hydrophilic, they do not cross the cell membrane and thus their message must be relayed to a second messenger on the inside. There are several second messenger pathways, each with their own way of relaying information. G-protein coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol path is active when the receptor induces phospholipase C to hydrolyze the phospholipid,...
81.8K
Transport Across the Golgi01:26

Transport Across the Golgi

4.0K
While it is unclear how molecules move between adjacent Golgi cisternae, it is apparent that the molecules move from cis- cisterna, the entry face, to the trans- cisterna, the exit face. Experiments initially suggested vesicles that bud from one cisterna and fuse with the next cisterna to transport proteins between the cisternae. This vesicular transport model describes the Golgi apparatus as a relatively static structure with a unique enzyme composition in each cisterna. Molecules are...
4.0K
Protein Transport to the Inner Chloroplast Membrane01:18

Protein Transport to the Inner Chloroplast Membrane

2.1K
Proteins targeted to the inner chloroplast membrane, or plastid proteins, are transported by two general pathways: the stop-transfer and the re-insertion or post-import pathways. Most plastid proteins carry N-terminal transit sequences and internal import sequences targeting it to the specific chloroplast subcompartment. Proteins targeted by the stop-transfer pathway have internal hydrophobic sequences that inhibit their translocation into the stroma. As a result, these precursors are arrested...
2.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Sp1 links CD46 to CD4 T cell metabolic fitness, survival, and retroviral control.

Science immunology·2026
Same author

Author Correction: Ontogeny and transcriptional regulation of Thetis cells.

Nature·2026
Same author

Proteomic Insights into Antimicrobial Resistance Mechanisms in Human-Associated Bacterial Pathogens.

Microbial ecology·2026
Same author

Correlation of CS and OCTA biomarkers in CSCR.

Romanian journal of ophthalmology·2026
Same author

Population immunity to clade 2.3.4.4b H5N1 is dominated by anti-neuraminidase antibodies.

mBio·2026
Same author

Author's response Comments on: Efficacy and safety of pilocarpine hydrochloride ophthalmic solution USP 1.25% w/v (PresVu eye drops) versus placebo ophthalmic solution for the treatment of presbyopia - A multicentric clinical trial.

Indian journal of ophthalmology·2026

Related Experiment Video

Updated: May 15, 2025

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
11:25

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

6.5K

Inside job: Roles of intracellular C3.

Behdad Afzali1, Parul Singh2, Md Tajmul1

  • 1Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Bethesda, Md.

The Journal of Allergy and Clinical Immunology
|April 7, 2025
PubMed
Summary

The complement system, particularly C3, plays crucial intracellular roles beyond pathogen defense. Further research into intracellular C3 functions and "C3 licensing" may reveal clinical implications.

Keywords:
C3 licensingComplementautophagycellular physiologycomplosomeintracellular C3metabolismmitochondria

More Related Videos

Author Spotlight: Innovative Approaches to Understanding Plant Structure-Function Relationships for Climate-Resilient Crops
06:04

Author Spotlight: Innovative Approaches to Understanding Plant Structure-Function Relationships for Climate-Resilient Crops

Published on: July 12, 2024

808
Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion
06:54

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Published on: June 15, 2019

5.9K

Related Experiment Videos

Last Updated: May 15, 2025

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins
11:25

Targeting Cysteine Thiols for in Vitro Site-specific Glycosylation of Recombinant Proteins

Published on: October 4, 2017

6.5K
Author Spotlight: Innovative Approaches to Understanding Plant Structure-Function Relationships for Climate-Resilient Crops
06:04

Author Spotlight: Innovative Approaches to Understanding Plant Structure-Function Relationships for Climate-Resilient Crops

Published on: July 12, 2024

808
Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion
06:54

Evaluation of the Interplay Between the Complement Protein C1q and Hyaluronic Acid in Promoting Cell Adhesion

Published on: June 15, 2019

5.9K

Area of Science:

  • Immunology
  • Cell Biology

Background:

  • The complement system was traditionally viewed as a liver-derived, systemic mechanism for pathogen clearance.
  • Recent findings reveal extensive extrahepatic and local complement production by various cells.
  • Emerging evidence highlights significant physiological intracellular roles for complement components.

Purpose of the Study:

  • To provide an overview of intracellular C3 forms, functions, and regulatory mechanisms.
  • To discuss emerging concepts like intracellular C3 in host-environmental defense and "C3 licensing."
  • To underscore the need for exploring clinical implications of intracellular C3 dysregulation.

Main Methods:

  • Literature review and synthesis of current research on intracellular complement.
  • Analysis of existing data on C3 production and function within cells.
  • Conceptual framework development for novel roles of intracellular C3.

Main Results:

  • Intracellular C3 is a critical regulator of basic cellular functions.
  • Complement components, including C3, are produced locally by many cell types.
  • Intracellular C3 has potential roles in host defense at interfaces and in cellular processes termed "C3 licensing."

Conclusions:

  • The complement system's functions extend significantly into intracellular biology.
  • Intracellular C3 represents a key area for future research with potential clinical relevance.
  • Further investigation into intracellular C3 activities and their perturbations is warranted.