# Regulation of intracellular transport

> **NIH NIH R01** · UNIVERSITY OF CONNECTICUT SCH OF MED/DNT · 2020 · $358,875

## Abstract

Project Summary
Intracellular transport is ubiquitous in animal cells and has fundamental importance for diverse biological
phenomena, such as secretion, neuronal signaling, organization of endomembranes, and mitosis. The driving
force for intracellular transport is provided by molecular motors bound to the surface of cargo organelles and
moving along microtubules (MTs) and actin filaments (AFs). Transport of specific organelles is generally driven
by several types of molecular motors simultaneously bound to their surface. Furthermore, the same cargo
often uses both types of cytoskeletal tracks for the movement. This remarkable complexity of transport
mechanisms requires precise regulation to ensure delivery to specific cellular destinations. Here, we propose
to examine the mechanisms of regulation of intracellular transport using Xenopus melanophores as an
experimental system. The major function of these cells is fast and synchronous redistribution of thousands of
membrane-bounded pigment granules, which aggregate in the cell center or uniformly disperse throughout the
cytoplasm by moving along MTs and AFs by means of cytoplasmic dynein (aggregation), and kinesin-2 and
myosin Va (dispersion). Switching between these motors and cytoskeletal systems is regulated by a single
second messenger, cAMP, and involves the activity of Protein Kinase A (PKA). Background data by the PI
indicate that changes in properties of MTs and AFs may play active role in regulation of pigment granule
transport. Preliminary data also indicate that PKA is bound to pigment granules where it forms complexes with
molecular motors that may include other protein kinases and phosphatases regulating motor activities. This
proposal will use a combination of molecular, cellular, and biochemical approaches to test the hypothesis that
aggregation and dispersion signals control redistribution of pigment granules through cooperation of two
interdependent mechanisms, regulation cytoskeletal tracks that provide rails for the movement, and molecular
motors that generate force for transport. Specific Aims of this grant application are: (1) To test the hypothesis
that transport of pigment granules is regulated by changes in availability and transport properties of MT and AF
tracks; (2) To test the hypothesis that regulation of pigment granule motility involves localized signaling
molecules bound to pigment granules that form complexes with molecular motors and control their activities.

## Key facts

- **NIH application ID:** 9828094
- **Project number:** 5R01GM062290-17
- **Recipient organization:** UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
- **Principal Investigator:** VLADIMIR I RODIONOV
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $358,875
- **Award type:** 5
- **Project period:** 2001-06-01 → 2022-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9828094

## Citation

> US National Institutes of Health, RePORTER application 9828094, Regulation of intracellular transport (5R01GM062290-17). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9828094. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*