Difference Between Tonofibrils and Tonofilaments - Testbook

Last Updated on Jul 31, 2023
Download As PDF
IMPORTANT LINKS

What are Tonofibrils?

Tonofibrils are protein structures primarily found in epithelial tissues. They connect at desmosomes and hemidesmosomes. Composed of thin fibrils, they connect to the cytoskeletal structures. Tonofilaments, which are keratin intermediate filaments, form tonofibrils in epithelial tissues. In simpler terms, tonofibrils are visible clusters of tonofilaments. Occasionally, a protein known as filaggrin binds with keratin intermediate filaments to form macro fibrils.


What are Tonofilaments?

Tonofilaments are keratin intermediate filaments found in epithelial tissues. They are made of keratin proteins and bundle together to form a tonofibril. Tonofilaments are especially noticeable under desmosomal plaques. They pass through the desmosomes in epithelial cells and interact with the intracellular proteins present in the plaques. Moreover, hemidesmosomes also interact with tonofilaments.

Comparing Tonofibrils and Tonofilaments

Tonofibrils

Tonofilaments

These are cytoplasmic structures that connect at desmosomes and hemidesmosomes.

These are keratin intermediate filaments that bundle up to form tonofibrils.

They are generally thicker than tonofilaments.

They are finer compared to tonofibrils.

Further Reading: Structure and Function of Cytoskeleton

Discover more interesting topics in Biology

More Articles for Key Differences

Frequently Asked Questions

They are specialised cell structures for adhesion. They are randomly arranged adhesion spots on the plasma membrane. Desmosomes are composed of keratin intermediate filaments and other proteins.

They are cytoskeletal structures composed of proteins. Some interact with the hemidesmosomes and desmosomes in the plasma membrane, and help in cell adhesion. They are found in the cells of most invertebrates and vertebrates.

Fibrils are thin structural units that are usually smaller than fibres. The diameter of a fibril ranges from 10-100 nanometres. Whereas the diameter of fibres is measured on micro to milli scale.

Filaggrin is a special protein that helps in the aggregation of filaments. Usually, it binds to the keratin filaments in epithelial cells. It is vital in regulating epidermal homeostasis.

Test Series
402.3k Students
SBI PO Mock Test Series 2025 (Pre + Mains)
367 TOTAL TESTS | 13 Free Tests
  • 13 Full Test (Mains)
  • 70 GA/CA Pack
  • 12 Sectional Test (Mains)
  • 89 Chapter Test
  • 2 2025 Trend Based FTs
  • 28 Full Test (Prelims)
  • 45 Most Saved Qs
  • 15 Sectional Test (Prelims)
  • 24 Memory Based Paper
  • 46 Memory Based Sectional Test
  • 23 IBPS Recent Exam MBTs

Get Started
Report An Error