| Phorbol esters/diacylglycerol binding domain (C1 domain) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 C1 domain of PKC-delta (1ptr)
Middle plane of the lipid bilayer - black dots. Boundary of the hydrocarbon core region - blue dots (cytoplasmic side). Layer of lipid phosphates - yellow dots. | |||||||||
| Identifiers | |||||||||
| Symbol | C1 | ||||||||
| Pfam | PF00130 | ||||||||
| InterPro | IPR002219 | ||||||||
| SMART | C1 | ||||||||
| PROSITE | PDOC00379 | ||||||||
| SCOP2 | 2cpk / SCOPe / SUPFAM | ||||||||
| OPM superfamily | 60 | ||||||||
| OPM protein | 1ptr | ||||||||
| CDD | cd00029 | ||||||||
| |||||||||
C1 domain (also known as phorbol esters/diacylglycerol binding domain) binds an important secondary messenger diacylglycerol (DAG), as well as the analogous phorbol esters.[1] Phorbol esters can directly stimulate protein kinase C, PKC.
Phorbol esters (such as PMA) are analogues of DAG and potent tumor promoters that cause a variety of physiological changes when administered to both cells and tissues. DAG activates a family of serine/threonine protein kinases, collectively known as protein kinase C (PKC). Phorbol esters can directly stimulate PKC.
The N-terminal region of PKC, known as C1, binds PMA and DAG in a phospholipid and zinc-dependent fashion.[2] The C1 region contains one or two copies of a cysteine-rich domain, which is about 50 amino-acid residues long, and which is essential for DAG/PMA-binding.
The DAG/PMA-binding domain binds two zinc ions; the ligands of these metal ions are probably the six cysteines and two histidines that are conserved in this domain.