In Golgi apparatus, the maturing face is ____________.

Question

Question

This question was previously asked in

SSC CGL 2022 Tier-I Official Paper (Held On : 01 Dec 2022 Shift 1)

Answer 1

The correct answer is concave.

Key Points

Concave or trans face of Golgi is maturing face which produce Golgian vacuoles.
The Golgi apparatus in animal cells is positioned near the centrosome-based microtubule organizing center.
Golgi pericentrosomal position is a striking feature of mammalian cells.
It is mostly the result of secretory and Golgi membrane movement toward the minus end of microtubules by the dynein motor complex.
Regulation of Golgi positioning is also important, it can occur at different stages of the cell cycle such as:
- Membrane association is regulated during mitosis.
- During cycles of membrane capture and release for inward secretory and Golgi movements.
Golgi positioning is maintained after inward movement by Golgi-nucleated microtubules.
Golgi positioning may be a consequence of a rearranged centrosome-meditated microtubule array.
Centrosome-meditated microtubule array orient their Golgi to perform directed secretion toward sites of rapid or specialized growth.

Screenshot 2024-08-20 222108

Important Points

STEP-1:

Newly synthesized proteins and lipids of the secretory pathway are packaged into membrane carriers that bud from the endoplasmic reticulum (ER).
These membranes fuse with each other and/or preexisting ER-Golgi intermediate compartment membranes (ERGIC).
ERGIC is transported along microtubules toward the centrosome by the dynein motor protein complex.

STEP-2:

Two models are suggested in this step:

By the cisternal progression model, the membranes generate new cis-Golgi cisternae as they near the centrosome. This is due to fusion with recycling vesicles bearing cis-Golgi components including processing enzymes.
By the Stable compartments model, the membranes fuse with preexisting cis-Golgi cisternae thereby delivering their content for processing.

By either model, the continuous inward movement of membrane carriers will contribute to the steady state localization of Golgi membranes near the centrosome.
This is principal because the membranes bear active dynein at the time of their delivery.
Dynein is likely recruited directly from the cytoplasm onto Golgi membranes.
Dynein further contributes to Golgi pericentrosomal positioning.