Protein Kinase A, which Regulates Intracellular Transport, Forms Complexes with Molecular Motors on Organelles
نویسندگان
چکیده
Major signaling cascades have been shown to play a role in the regulation of intracellular organelle transport . Aggregation and dispersion of pigment granules in melanophores are regulated by the second messenger cAMP through the protein kinase A (PKA) signaling pathway ; however, the exact mechanisms of this regulation are poorly understood. To study the role of signaling molecules in the regulation of pigment transport in melanophores, we have asked the question whether the components of the cAMP-signaling pathway are bound to pigment granules and whether they interact with molecular motors to regulate the granule movement throughout the cytoplasm. We found that purified pigment granules contain PKA and scaffolding proteins and that PKA associates with pigment granules in cells. Furthermore, we found that the PKA regulatory subunit forms two separate complexes, one with cytoplasmic dynein ("aggregation complex") and one with kinesin II and myosin V ("dispersion complex"), and that the removal of PKA from granules causes dissociation of dynein and disruption of dynein-dependent pigment aggregation. We conclude that cytoplasmic organelles contain protein complexes that include motor proteins and signaling molecules involved in different components of intracellular transport. We propose to call such complexes 'regulated motor units' (RMU).
منابع مشابه
The Molecular Motor Toolbox for Intracellular Transport
Eukaryotic cells create internal order by using protein motors to transport molecules and organelles along cytoskeletal tracks. Recent genomic and functional studies suggest that five cargo-carrying motors emerged in primitive eukaryotes and have been widely used throughout evolution. The complexity of these "Toolbox" motors expanded in higher eukaryotes through gene duplication, alternative sp...
متن کاملIntracellular transport and kinesin superfamily proteins, KIFs: structure, function, and dynamics.
Various molecular cell biology and molecular genetic approaches have indicated significant roles for kinesin superfamily proteins (KIFs) in intracellular transport and have shown that they are critical for cellular morphogenesis, functioning, and survival. KIFs not only transport various membrane organelles, protein complexes, and mRNAs for the maintenance of basic cellular activity, but also p...
متن کاملCellular SRC kinases and dsRNA dependent protein kinase (PKR) play key role in intracellular viral (CVB3) replication
SRC kinases and PKR are intracellular protein kinases, which play key roles in intracellular viral replication. In this research, the effect of SRC kinase inhibition and PKR activation and inhibition on replication of coxsakievirus (CVB3), an entrovirus of the family picornaviridae – causative agents of fatal myocarditis, was studied. Vero and Hela cells were cultured and infected with CVB3 in ...
متن کاملUNC-51/ATG1 kinase regulates axonal transport by mediating motor-cargo assembly.
Axonal transport mediated by microtubule-dependent motors is vital for neuronal function and viability. Selective sets of cargoes, including macromolecules and organelles, are transported long range along axons to specific destinations. Despite intensive studies focusing on the motor machinery, the regulatory mechanisms that control motor-cargo assembly are not well understood. Here we show tha...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Current Biology
دوره 14 شماره
صفحات -
تاریخ انتشار 2004