Cell-penetrating SH3 domain blocker peptides inhibit proliferation of primary blast cells from CML patients.
Bcr-Abl contributes prominently to the development of most chronic myeloid leukemias (CMLs). Prior work has identified the adapter protein CRKL as a major substrate of the Bcr-Abl tyrosine kinase. CRKL can also bind via its first SH3 domain [SH3(1)] to specific sequences in Bcr-Abl. Cell-penetrating peptides were developed that bind with high affinity and selectivity to the SH3(1) domain of CRKL. They disrupt Bcr-Abl-CRKL complexes and strongly reduce the proliferation of primary CML blast cells and cell lines established from Bcr-Abl-positive patients. Activation-specific antibodies against phosphorylated MAP kinase (MAPK) showed that MAPK activity is down-regulated in blast cells treated with the CRKLSH3(1) blocker peptides. We conclude that the Bcr-Abl-CRKL complexes are largely dependent on the CRKLSH3(1) domain, that the central mitogenic cascade is down-regulated as a consequence of the disruption of CRKLSH3(1) interactions, and that CRKL therefore contributes to the proliferation of CML blast cells.
Laboratory of Molecular Oncology, MSZ, Universität Würzburg, Germany.
C
C
Kardinal
B
B
Konkol
A
A
Schulz
G
G
Posern
H
H
Lin
K
K
Adermann
M
M
Eulitz
Z
Z
Estrov
M
M
Talpaz
R B
RB
Arlinghaus
S M
SM
Feller
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000378:metabolism / Q000494:pharmacology; D037282:Calreticulin; D002455:Cell Division / Q000187:drug effects; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D005455:Fluorescent Antibody Technique; D016044:Fusion Proteins, bcr-abl / Q000037:antagonists & inhibitors / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D008213:Lymphocyte Activation / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism* / Q000493:pharmacokinetics / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology; D012261:Ribonucleoproteins / Q000378:metabolism / Q000494:pharmacology; D013050:Spectrometry, Fluorescence; D014407:Tumor Cells, Cultured; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; C082869:CRKL protein; D002135:Calcium-Binding Proteins; D037282:Calreticulin; D009687:Nuclear Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D016044:Fusion Proteins, bcr-abl; D020928:Mitogen-Activated Protein Kinases