A complex composed of RNA of the small nucleolar RNA (snoRNA) and protein, found in the nucleolus of a eukaryotic cell. Most are involved in a step of processing of rRNA: cleavage, 2'-O-methylation, or pseudouridylation. The majority, though not all, fall into one of two classes, box C/D type or box H/ACA type.

The regulated release of a peptide hormone from secretory granules.

The regulated release of proinsulin from secretory granules (B granules) in the B cells of the pancreas; accompanied by cleavage of proinsulin to form mature insulin.

RNA polymerase I, one of three eukaryotic nuclear RNA polymerases, is a multisubunit complex; it produces rRNAs. Two large subunits comprise the most conserved portion including the catalytic site and share similarity with other eukaryotic and bacterial multisubunit RNA polymerases. The remainder of the complex is composed of smaller subunits (generally ten or more), some of which are also found in RNA polymerase III and others which are found in all three nuclear RNA polymerases. Although the core is competent to mediate ribonucleic acid synthesis, it requires additional factors to select the appropriate template.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

Interacting selectively with a SMAD signaling protein.

The transfer, from NAD, of ADP-ribose to peptidyl-arginine to form omega-N-(ADP-ribosyl)-L-arginine.

Catalysis of the reaction: P1-P3-bis(5'-adenosyl) triphosphate + H2O = ADP + AMP.

extracellular matrix structural constituent conferring tensile strength

A constituent of the extracellular matrix that enables the matrix to resist longitudinal stress.

extracellular matrix structural constituent conferring compression resistance

A constituent of the extracellular matrix that enables the matrix to resist compressive forces; often a proteoglycan.