What is Golgi apparatus and Endoplasmic reticulum?

Do microtubules connect both the endoplasmic reticulum and the golgi apparatus?

• And are all organelles practically connected to each other through them? Correctly folded and assembled proteins in the ER are packaged into COPII-coated transport vesicles that pinch off from the ER membrane. Shortly thereafter the coat is shed and the vesicles fuse with one another to form vesicular tubular clusters, which move on microtubule tracks to the Golgi apparatus. Many resident ER proteins slowly escape, but they are returned to the ER from the vesicular tubular clusters and the Golgi apparatus by retrograde transport in COPI-coated vesicles.

• Answer:

  I am not sure about the ER, but the Golgi is definitively linked with microtubules through p230/Golgin-245 and MACF1 proteins. Please see this paper: http://www.sciencedirect.com/science/article/pii/S0014482704002502. The Golgi is positioned close to the MTOC (microtubule organizing center), see http://jcs.biologists.org/content/118/10/2279.full and refererences therein.