Rab effector MyRIP

Rab effector MyRIP (MYRIP) is a 859-amino acid Rab effector protein that mediates melanosome transport by linking the vesicle-bound GTPase RAB27A to motor proteins MYO5A and MYO7A, thereby coupling RAB27A-containing vesicles to actin filaments (UniProt: Q8NFW9). The protein also functions as a protein kinase A-anchoring protein (AKAP), potentially scaffolding PKA to exocytotic machinery and facilitating regulated secretion including insulin release. MYRIP is expressed in tissues requiring vesicular transport and secretion.

MYRIP shows reduced abundance in Alzheimer's Disease brain tissue. In human post-mortem AD brain compared to age-matched controls, MYRIP is significantly down-regulated (mean log2 fold-change: −0.39; Chaparral AD proteomics, TMT-labeled DDA proteomics across four subcellular fractions). This down-regulation suggests altered vesicular trafficking or exocytotic capacity may contribute to AD pathology, though the functional consequences remain to be determined.