A structure found most metazoan nucleoli, but not usually found in lower eukaryotes; surrounded by the dense fibrillar component; the zone of transcription from multiple copies of the pre-rRNA genes is in the border region between these two structures.

A G protein-coupled receptor activity that is activated by cleavage by a serine protease, exposing a tethered ligand corresponding to the new N-terminus, which binds to the receptor and activates it.

The process whereby a relatively unspecialized cell acquires the specialized features of an osteoblast, a mesodermal or neural crest cell that gives rise to bone.

Combining with cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) and transmitting the signal from one side of the membrane to the other to initiate a change in cell activity.

Combining with cytokinin and transmitting the signal across the membrane by activating an associated G-protein; promotes the exchange of GDP for GTP on the alpha subunit of a heterotrimeric G-protein complex.

A G protein-coupled receptor that is activated by L-AP-4 and inhibits adenylate cyclase activity.

Combining with glutamate and transmitting the signal across the membrane by activating the alpha-subunit of an associated heterotrimeric G-protein complex to inhibit downstream adenylate cyclase activity.

A G protein-coupled receptor that is activated by trans-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) and inhibits adenylate cyclase activity.

A G protein-coupled receptor that binds glutamate and is linked to the inositol 1,4,5-trisphosphate/calcium signaling system.

Combining with a calcitonin gene-related polypeptide (CGRP) to initiate a change in cell activity.

OBSOLETE. (Was not defined before being made obsolete).

OBSOLETE. A G protein-coupled receptor that is structurally/functionally related to the secretin receptor.

A G protein-coupled receptor that interacts with pituitary adenylate cyclase-activating polypeptide.

Combining with a cysteinyl leukotriene to initiate a change in cell activity. Cysteinyl leukotrienes are leukotrienes that contain a peptide group based on cysteine.

Combining with leukotriene B4, LTB4, to initiate a change in cell activity. Leukotriene B4 is also known as (6Z, 8E, 10E, 14Z)-(5S, 12R)-5,12-dihydroxyicosa-6,8,10,14-tetraen-1-oate.

OBSOLETE. (Was not defined before being made obsolete).