# ASSAYS FOR AND MECHANISMS OF ACTION OF TUMOR PROMOTERS

> **NIH NIH R01** · PACIFIC NORTHWEST RESEARCH INSTITUTE · 1991 · $205,286

## Abstract

The growth division cycle of non-neoplastic cells is regulated by a
variety of proteins as well as ions, small peptides and phospholipid
products.  Protein function can be regulated by binding to other proteins
or by phosphorylation/dephosphorylation.  While the past decade has
focused on protein kinases in the regulation of cell proliferation and
tumor promotion, recent evidence points to the importance of protein
phosphatases in regulation of the cell cycle and in the tumor promotion
process.
     We have found a novel serine/threonine protein phosphatases, type 3,
that differs at the biochemical and molecular level from the other known
protein phosphatases (PP) 1, 2A, 2B and 2C.  Okadaic acid is a
non-phorbol ester tumor promoter whose intracellular receptor is PP1,
PP2A and PP3, having different affinities for these three enzymes and
inhibiting their activities.  It is the specific focus of this proposal
to: 1) clone a cDNA of PP3 and relate the expression of this gene as well
as PP1 and PP2A genes to the cell cycle and carcinogenesis; 2) define the
role of PP1, PP2A and PP3 in cell cycle progression; 3) determine the
role of PP1, PP2A and PP3 in generation of intracycle Ca2+ transients and
4) determine how PP3 catalytic activity is regulated and identify
subcellular substrates of PP3.

## Key facts

- **NIH application ID:** 3179133
- **Project number:** 2R01CA039745-07
- **Recipient organization:** PACIFIC NORTHWEST RESEARCH INSTITUTE
- **SAM.gov UEI:** HJQSAMLJY9M3
- **Principal Investigator:** ALTON L BOYNTON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $205,286
- **Award type:** 2
- **Project period:** 1985-08-21 → 1995-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3179133

## Citation

> US National Institutes of Health, RePORTER application 3179133, ASSAYS FOR AND MECHANISMS OF ACTION OF TUMOR PROMOTERS (2R01CA039745-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3179133. Licensed CC0.

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