High impact information on Rabac1

• The interaction of these small GTPases with PRA1 requires their post-translational modification by prenylation [1].
• The amino acid sequence of the protein portion of mp58 as deduced from the DNA sequence of its encoding gene (FBP1/PRA1) was used to synthesize a complete set of overlapping dodecapeptides (overlap, 7; offset, 5) covalently attached to the surface of derivatized polyethylene pins [2].
• However, deletion of Val185 has only moderate effect on the ER export of prenylin, suggesting that this valine residue is not part of an export signal itself; instead, it may affect the folding and conformation of prenylin [3].
• This region contains a di-acidic motif (Asp176-Xaa-Glu), but changing either acidic residue to alanine has no effect on the ER export of prenylin [3].
• Thus we have identified a single C-terminal valine residue that is essential for the proper dimerization and ER export of prenylin [3].

Biological context of Rabac1

• Alanine-scanning mutagenesis of the entire C-terminal region reveals that only the very C-terminal Val185 residue is crucial for the ER export of prenylin [3].

Anatomical context of Rabac1

• Prenylin [or prenylated Rab acceptor 1 (PRA1)] is a multi-pass transmembrane protein that initially inserts into the ER (endoplasmic reticulum) membrane, followed by vesicular transport along the exocytic pathway to the Golgi complex where it may regulate the functions of prenylated proteins [3].

Analytical, diagnostic and therapeutic context of Rabac1

• We have employed site-directed mutagenesis to investigate the role of each of the C-terminal 10 residues in the ER export of prenylin [3].

References