Related Experiment Video

Updated: Sep 20, 2026

Development and Application of Rapamycin-regulated Tyrosine Phosphatases
06:56

Development and Application of Rapamycin-regulated Tyrosine Phosphatases

Published on: September 6, 2024

A bad rap: Rap1 signaling and oncogenesis

David A Largaespada1

  • 1University of Minnesota Cancer Center, 6-160 Jackson Hall, 321 Church Street S.E., Minneapolis, MN 55455, USA. larga002@tc.umn.edu

Cancer Cell
|August 2, 2003
PubMed

Insights

Targeting the SPA-1 gene in mice caused Rap1 hyperactivation in hematopoietic cells, leading to myeloid diseases. This study highlights Rap1 activation

Area of Science:

  • Hematology
  • Oncology
  • Molecular Biology

Background:

  • The study investigates the role of SPA-1, a Rap1-specific GTPase-activating protein (GAP), in hematopoietic cell regulation.
  • Dysregulation of Rap1 signaling is implicated in various myeloid disorders.

Discussion:

  • Targeted inactivation of the SPA-1 gene in mice resulted in Rap1 hyperactivation within hematopoietic cells.
  • This sustained hyperactivation mimicked features of human myeloid dysplastic and proliferative diseases.
  • The findings suggest SPA-1 is a critical negative regulator of Rap1 in myelopoiesis.

Key Insights:

  • Rap1 hyperactivation, driven by SPA-1 deficiency, contributes to the development of myeloid malignancies.
  • The level of Rap1 activation is crucial for normal myelopoiesis.
  • SPA-1 inactivation can provide an oncogenic signal in the context of myeloid cell development.

Outlook:

  • This research may pave the way for novel therapeutic strategies targeting the Rap1 pathway in myeloid cancers.
  • Further investigation into SPA-1's precise role in oncogenesis is warranted.

More Related Videos

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants07:38

Intracellular Phosphoflow Cytometry of Acute Myeloid Leukemia Patient-Derived Xenotransplants

Published on: June 6, 2025

Identification of Transcription Factor Regulators using Medium-Throughput Screening of Arrayed Libraries and a Dual-Luciferase-Based Reporter11:32

Identification of Transcription Factor Regulators using Medium-Throughput Screening of Arrayed Libraries and a Dual-Luciferase-Based Reporter

Published on: March 27, 2020

Related Concept Videos

mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Abnormal Proliferation02:23

Abnormal Proliferation

Under normal conditions, most adult cells remain in a non-proliferative state unless stimulated by internal or external factors to replace lost cells. Abnormal cell proliferation is a condition in which the cell's growth exceeds and is uncoordinated with normal cells. In such situations, cell division persists in the same excessive manner even after cessation of the stimuli, leading to persistent tumors. The tumor arises from the damaged cells that replicate to pass the damage to the daughter...