Hedgehog Protein Processing Concepts

The video tutorial explains the formation and processing of the hedgehog precursor protein in cells. It describes the protein's n-terminal and c-terminal fragments, their molecular weights, and amino acid counts. The auto processing domain's enzymatic activity is highlighted, focusing on the nucleophilic attack between glycine 257 and cysteine 258, leading to a biochemical reaction with cholesterol. This results in auto cleavage, producing two fragments. The n-terminal fragment signals other cells, while the c-terminal is degraded. The hedgehog protein undergoes palmitoylation, becoming more hydrophobic and tethered to the plasma membrane.

What are the two main fragments of the hedgehog precursor protein?

• N-terminal and C-terminal fragments

• Alpha and Beta fragments

• Gamma and Delta fragments

• Primary and Secondary fragments

What is the molecular weight of the N-terminal fragment?

• 471 kilodalton

• 45 kilodalton

• 20 kilodalton

• 83 kilodalton

How many amino acids are present in the C-terminal fragment?

• 257

• 83

• 258

• 471

What is the role of the auto-processing domain in the hedgehog precursor protein?

• It signals other cells

• It degrades the protein

• It has enzymatic activity

• It binds to cholesterol

What type of attack occurs between cysteine 258 and glycine 257?

• Electrophilic attack

• Nucleophilic attack

• Hydrophobic attack

• Oxidative attack

What bond is formed between cholesterol and glycine 257?

• Ionic bond

• Ester bond

• Hydrogen bond

• Peptide bond

What happens to the C-terminal fragment after auto-cleavage?

• It binds to the plasma membrane

• It is secreted to signal other cells

• It is degraded

• It undergoes palmitoylation

What is the purpose of palmitoylation in the hedgehog protein?

• To degrade the protein

• To make the protein more hydrophilic

• To signal other cells

• To make the protein more hydrophobic

Which enzyme catalyzes the palmitoylation process?

• Cholesterol synthase

• Protein kinase

• Hedgehog acyle transferase

• Lipid transferase

Where is the fully processed hedgehog protein tethered?

• Plasma membrane

• Nucleus

• Mitochondria

• Endoplasmic reticulum