Normal thyroid structure and function in rhophilin 2-deficient mice.
Rhophilin 2 is a Rho GTPase binding protein initially isolated by differential screening of a chronically thyrotropin (TSH)-stimulated dog thyroid cDNA library. In thyroid cell culture, expression of rhophilin 2 mRNA and protein is enhanced following TSH stimulation of the cyclic AMP (cAMP) transduction cascade. Yeast two-hybrid screening and coimmunoprecipitation have revealed that the GTP-bound form of RhoB and components of the cytoskeleton are protein partners of rhophilin 2. These results led us to suggest that rhophilin 2 could play an important role downstream of RhoB in the control of endocytosis during the thyroid secretory process which follows stimulation of the TSH/cAMP pathway. To validate this hypothesis, we generated rhophilin 2-deficient mice and analyzed their thyroid structure and function. Mice lacking rhophilin 2 develop normally, have normal life spans, and are fertile. They have no visible goiter and no obvious clinical signs of hyper- or hypothyroidism. The morphology of thyroid cells and follicles in these mice were normal, as were the different biological tests performed to investigate thyroid function. Our results indicate that rhophilin 2 does not play an essential role in thyroid physiology.
Behrends
Jens
J
IRIBHM, IBMM, rue des Professeurs Jeener et Brachet 12, 6041-Gosselies, Belgium.
Clément
Serge
S
Pajak
Bernard
B
Pohl
Viviane
V
Maenhaut
Carine
C
Dumont
Jacques E
JE
Schurmans
Stéphane
S
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001921:Brain / Q000166:cytology / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D005838:Genotype; D017874:Immediate-Early Proteins / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D008168:Lung / Q000166:cytology / Q000378:metabolism; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000166:cytology / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*
D048868:Adaptor Proteins, Signal Transducing; D018076:DNA, Complementary; D017874:Immediate-Early Proteins; C499658:Rhpn2 protein, mouse; C097916:rhophilin; D017346:Protein Serine-Threonine Kinases