Two major classes of actin-nucleating proteins:

1. Formins nucleate the assembly of unbranched filaments 

2. Arp2/3 complex nucleates the assembly of branched actin networks

TLS Online TPP Program

#Id: 8189

#Section 3: Genetics, Cellular and Molecular Biology

C-terminal peroxisomal signal sequences Ser–Lys–Leu (PTS1)

N-terminal peroxisomal signal sequences slightly longer and partially hydrophobic (PTS2)

TLS Online TPP Program

#Id: 8188

#Section 3: Genetics, Cellular and Molecular Biology

Plasmalogens

• most abundant class of PL in myelin sheaths

• Analogous to PC

• Contain an unusual fatty alcohol that is attached through an ether linkage.

TLS Online TPP Program

#Id: 8187

#Section 3: Genetics, Cellular and Molecular Biology

Biosynthetic function of animal peroxisomes- 

Synthesis of cholesterol and dolichol 

Synthesis of bile acids in the liver 

Catalyze the first reactions in the formation of Plasmalogens

TLS Online TPP Program

#Id: 8186

#Section 3: Genetics, Cellular and Molecular Biology

Glyoxysomes

Conversion of fats to sugars is accomplished by a series of reactions known as the Glyoxylate cycle

TLS Online TPP Program

#Id: 8185

#Section 3: Genetics, Cellular and Molecular Biology

Two types of plant peroxisomes:

Present in leaves - participates in photorespiration.

Present in germinating seeds (glyoxysomes) - converts fatty acids into sugars.

TLS Online TPP Program

#Id: 8184

#Section 3: Genetics, Cellular and Molecular Biology

β oxidation

In mammalian cells, occurs in mitochondria & peroxisomes.

In yeast and plant cells, occurs in peroxisomes.