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Full-Text Articles in Physiology
Examination Of Anabolic Signaling And Muscle Growth With Caffeine Treatment In Overloaded Hindlimb Muscle And Electrically Stimulated Muscle Lacking Liver Kinase B1, Timothy Michael Moore
Examination Of Anabolic Signaling And Muscle Growth With Caffeine Treatment In Overloaded Hindlimb Muscle And Electrically Stimulated Muscle Lacking Liver Kinase B1, Timothy Michael Moore
Theses and Dissertations
Skeletal muscle has the ability to increase in size (hypertrophy) after resistance is placed upon it. This hypertrophy is marked by significant upregulation of the mammalian target of rapamycin (mTOR) and its downstream targets. The upstream kinases, protein kinase B (also known as Akt) and AMP-activated protein kinase (AMPK), are two of the many regulators of the mTOR pathway. Recent studies suggest that the widely consumed neuroactive compound caffeine could potentially inhibit mTOR by acting through Akt and/or AMPK. The purpose of this thesis was to: 1) determine if caffeine can inhibit the mTOR pathway and ultimately attenuate skeletal muscle …
Characterization Of The Lkb1-Mo25-Strad Ampkk Complex In Adult Mouse Skeletal Muscle, Cody Don Smith
Characterization Of The Lkb1-Mo25-Strad Ampkk Complex In Adult Mouse Skeletal Muscle, Cody Don Smith
Theses and Dissertations
In liver tissue, the AMP-activated protein kinase kinase (AMPKK) complex was identified as the association of LKB1, MO25α/β, and STRADα/β proteins; however, this complex has yet to be characterized in skeletal muscle. In this report, we demonstrate the expression of the LKB1-MO25-STRAD AMPKK complex in adult skeletal muscle, confirm the absence of mRNA splice variants, and report the relative mRNA expression levels of these complex-forming proteins. To facilitate this characterization we used control (ctrl) and muscle-specific LKB1 knockout (LKB1-/-) mice. LKB1 detection in untreated ctrl and LKB1-/- muscle lysates revealed two protein bands at approximately 50 and 60 kDa; although, …
Amp-Activated Protein Kinase Kinase Activity And Phosphorylation Of Amp-Activated Protein Kinase In Contracting Muscle Of Sedentary And Endurance Trained Rats, Denise Hurst
Theses and Dissertations
This study was designed to examine activity of AMP-activated protein kinase kinase (AMPKK) and AMP-activated protein kinase (AMPK) in muscles from control (C) and endurance trained (T) rats. Rats were trained 5 days/wk, 2 hr/d for 8 wks at a final intensity of 32 m/min up a 15% grade with 30 second sprints at 52 m/min every 10 min. Gastrocnemius muscles were stimulated in situ in T and C rats for 5 min at frequencies of 0.4/sec and 1/sec. Gastrocnemius LKB1 protein, a putative component of the AMPKK complex (LKB1, STRAD, and MO25), increased approximately 2-fold in response to training. …
Regulation Of Lkb1-Strad-Mo25 Complex Expression And Activation Of Ampk In Skeletal Muscle By Thyroid Hormone, Devon Jack Branvold
Regulation Of Lkb1-Strad-Mo25 Complex Expression And Activation Of Ampk In Skeletal Muscle By Thyroid Hormone, Devon Jack Branvold
Theses and Dissertations
AMP-activated protein kinase (AMPK), a heterotrimeric protein which serves as a metabolic master switch in skeletal muscle, is a research target for the pharmaceutical treatment and prevention of type 2 diabetes. The expression of all of the isoforms of the subunits of AMPK and AMPK activity are increased in skeletal muscle tissue of hyperthyroid rats. Activity of AMPK is regulated by an upstream kinase (AMPKK). The LKB1-STRAD-MO25 complex is a major AMPKK in skeletal muscle. This experiment was designed to determine whether the increase in AMPK activity is accompanied by a thyroid hormone-induced increase in the expression of the LKB1-STRAD-MO25 …
Pka As An Upstream Kinase For Lkb1/Strad/Mo25, Seth Taylor Herway
Pka As An Upstream Kinase For Lkb1/Strad/Mo25, Seth Taylor Herway
Theses and Dissertations
The LKB1/STRAD/MO25 complex (LSMK) has been identified as the major upstream kinase for AMP-activated protein kinase (AMPK). PKA phosphorylates LKB1 at the Ser428 residue in humans and Ser431 residue in mice. We investigated PKA as an upstream kinase for LSMK. LKB1 that had been incubated with PKA prior to incubation with AMPK experienced up to a 51% increase in AMPK Kinase activity compared to LKB1 alone (p < 0.05). When blocked with a PKA Inhibitor, the kinase effect of PKA on LKB1 was eliminated. Rat epitrochlearis muscle tissue incubated with epinephrine experienced no increase in AMPK activity compared with controls indicating that epinephrine does not cause AMPK activity in this type of tissue. In conclusion, phosphorylation by PKA can increase the AMPKK activity of LKB1-STRAD-MO25 in vitro. Because LKB1 has been found to be constitutively active, it is postulated that phosphorylation by PKA may act to enhance LKB1-AMPK interaction and thus achieve its effect.