protein kinase C conserved region 1 (C1 domain) found in the Ras association domain-containing protein 1 (RASSF1)-like family
The RASSF1-like family includes RASSF1 and RASSF5. RASSF1 and RASSF5 are members of a family of RAS effectors, of which there are currently 8 members (RASSF1-8), all containing a Ras-association (RA) domain of the Ral-GDS/AF6 type. RASSF1 has eight transcripts (A-H) arising from alternative splicing and differential promoter usage. RASSF1A and 1C are the most extensively studied RASSF1; both are localized to microtubules and involved in the regulation of growth and migration. RASSF1 is a potential tumor suppressor that is required for death receptor-dependent apoptosis. RASSF5, also called new ras effector 1 (NORE1), or regulator for cell adhesion and polarization enriched in lymphoid tissues (RAPL), is expressed as three transcripts (A-C) via differential promoter usage and alternative splicing. RASSF5A is a pro-apoptotic Ras effector and functions as a Ras regulated tumor suppressor. RASSF5C is regulated by Ras related protein and modulates cellular adhesion. RASSF5 is a potential tumor suppressor that seems to be involved in lymphocyte adhesion by linking RAP1A activation upon T-cell receptor or chemokine stimulation to integrin activation. RASSF1 and RASSF5 contain a C1 domain, which is descibed in this model. The C1 domain is a cysteine-rich zinc binding domain that does not bind DNA nor possess structural similarity to conventional zinc finger domains; it contains two separate Zn(2+)-binding sites.