lipid-dependent surface transport of the proton pumping

Lipid-dependent surface transport of the proton pumping

ATPase: A model to study plasma membrane biogenesis in yeast

Fan Mengdi Li Yandi

The Points

Introduction Biogenesis and transport of the

proton pumping H+-ATPase

The general introduction of the H+-ATPase in yeast

A good model to study plasma membrane biogenesis

The function of ATPase :

maintenance of the electrochemical gradient across the membrane

regulating intracellular PH

symporters

The general introduction

How did the H+-ATPase transport to the plasma membrane?

Begin: oligomerization and package

Surface transport of the ATPase

Raft association

Stable integrate at the plasma membrane

protein

lipid

Every step needs the help of these lipids:

How did the H+-ATPase transport to the plasma membrane?

sterolssphingolipids

Step 1: oligomerization

protein lipidProtein-lipid complex

In the ER, Pma1form a homo-oligomeric complex—the protein-lipid complex

The ER

C26Pma1

The ER

coat protein complex II(a kind of transport vesicle)

Step 2: package

Protein-lipid complex

The protein-lipid complex then packaged into a larger subclass of COPII

Step 3: modify of the Pma1

coat protein complex II

Protein-lipid complex

The Pma1 becomes phosphorylated on multiple serine and threonine residues

P-

Step 4: Pma1 transport to the cell surface

coat protein complex II

Protein-lipid complex

C26

Pma1 is transported to the cell surface

Every step needs the help of these lipids:

How did the H+-ATPase transport to the plasma membrane?

sterolssphingolipids

Step 5: Stable integrate at the plasma membrane

H+

ATP

Lipid raft association

C26

Two mutant of Pma1

Affect the stability, targeting, and detergent solubility during its transport to the surface

The first mutant:Pmal-7

coat protein complex II

Protein-lipid complex

Pmal-7:mistargeted from the Golgi to the vacuole without reaching the cell surface.

Vacuole

The second mutant:Pmal-10

C26

vacuole

Pmal-10: fails to become stabilized on the membrane, but to delivered to the vacuole, then degradation.

Two mutant of Pma1

. The mutant indicate: lipid raft association may play important roles in maintaining protein stability at the plasma membrane.