In this work, we analysed processive sliding and breakage of actin filaments at various heavy meromyosin (HMM) densities and ATP concentrations in IVMA. We observed that with addition of ATP solution, the actin filaments fragmented stochastically; we then determined mean length and velocity of surviving actin filaments post breakage. Average filament length decreased with increase in HMM density at constant ATP, and increased with increase in ATP concentration at constant HMM density. Using density of HMM molecules and length of actin, we estimated the number of HMM molecules per actin filament (N) that participate in processive sliding of actin. N is solely a function of ATP concentration: 88 ± 24 and 54 ± 22 HMM molecules (mean ± S.D.) at 2 mM and 0.1 mM ATP respectively. Processive sliding of actin filament was observed only when N lay within a minimum lower limit (Nmin) and a maximum upper limit (Nmax) to the number of HMM molecules. When N < Nmin the actin filament diffused away from the surface and processivity was lost and when N > Nmax the filament underwent breakage eventually and could not sustain processive sliding. We postulate this maximum upper limit arises due to increased number of strongly bound myosin heads.

Lysine is the first limiting essential amino acid in rice because it is present in the lowest quantity compared to all the other amino acids. Amino acids are the building block of proteins and play an essential role in maintaining the human body’s healthy functioning. Rice is a staple food for more than half of the global population; thus, increasing the lysine content in rice will help improve global health. In this paper, we studied the lysine biosynthesis pathway in rice (Oryza sativa) to identify the regulators of the lysine reporter gene LYSA (LOC_Os02g24354). Genetically intervening at the regulators has the potential to increase the overall lysine content in rice. We modeled the lysine biosynthesis pathway in rice seedlings under normal and saline (NaCl) stress conditions using Bayesian networks. We estimated the model parameters using experimental data and identified the gene DAPF(LOC_Os12g37960) as a positive regulator of the lysine reporter gene LYSA under both normal and saline stress conditions. Based on this analysis, we conclude that the gene DAPF is a potent candidate for genetic intervention. Upregulating DAPF using methods such as CRISPR-Cas9 gene editing strategy has the potential to upregulate the lysine reporter gene LYSA and increase the overall lysine content in rice.

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elucidated that the 75kDa protein are located on the membrane of muscle fiber but the 150 kDa protein are localized at the Z-line of the sarcomere. The localization of these proteins are also confirmed by the transfection of GFP-fusion proteins into cultured skeletal muscle cells. These insights indicate that novel proteins that transcribed from the contiguous genes of connectin gene exist in striated muscles. 2117-Pos Board B254Skeletal Myosin Binding Protein-C Isoforms Modulate Actomyosin Contractility and are Regulated by Phosphorylation Myosin binding protein C (MyBP-C) is a thick filament-associated protein found in striated muscle and may regulate muscle contractility. Separate genes encode the fast and slow skeletal isoforms, and there are potential PKA phosphorylation sites in their functionally important N-terminal regions. Here, we compare mouse N-terminal fast (fC1C2) and slow (sC1C2) skeletal fragments containing the initial~50 aa Pro/Ala-rich domain and the C1 and C2 Igdomains that are linked by the~100 aa M-domain. Of the known slow skeletal splice variants, we chose a highly expressed variant lacking the N-terminal 34-59 residue insert. To define the potential mechanisms by which skeletal MyBP-Cs affect contractility and whether these effects are modulated by PKA phosphorylation, we assessed the Ca 2þ -dependent motility of rabbit skeletal native thin filaments over a surface of rabbit psoas myosin in the presence of C1C2 fragments. While thin filaments were fully regulated, with no motion observed at pCa > 7 in the absence of fragments, the addition of either 0.50 mM fC1C2 or sC1C2 resulted in significant motility. This suggests that skeletal MyBP-C isoforms effectively sensitize the thin filament. Under fully activating conditions (pCa % 5), sC1C2 had little effect on motility whereas fC1C2 inhibited sliding velocities by nearly 50%. Thus, these fragments differ in their modulatory capacities with fC1C2 sensitizing the thin filament to Ca 2þ and inhibiting maximal velocities, while the sC1C2 variant exhibits only a single mode of contractile modulation; i.e. thin filament sensitization. Interestingly, PKA phosphorylation in the Pro/Ala (sC1C2) and M-domains (sC1C2 and fC1C2), as confirmed by mass spectrometry, reduced both fragments' Ca 2þ sensitization of the thin filament. Thus, the function of MyBP-C isoforms may be tuned to match the physiological demands of the muscle in which they are expressed.

Lysine is the first limiting essential amino acid in rice because it is present in the lowest quantity compared to all the other amino acids. Amino acids are the building block of proteins and play an essential role in maintaining the human body&rsquo;s healthy functioning. Rice is a staple food for large proportion of the global population, thus increasing the lysine content in rice will improve its nutritional value. In this paper, we studied the lysine biosynthesis pathway in rice (Oryza Sativa) to identify the regulators of the lysine reporter gene LYSA (LOC_Os02g24354). Genetically intervening at the regulators has the potential to increase the overall lysine content in rice. We modeled the lysine biosynthesis pathway in rice seedlings under normal and saline (NaCl) stress conditions using Bayesian networks. We estimated the model parameters using experimental data and identified the gene DAPF(LOC_Os12g37960) as a positive regulator of the lysine reporter gene LYSA under both normal and saline stress conditions. Based on this analysis, we conclude that the gene DAPF is a potent candidate for genetic intervention. Upregulating DAPF using methods such as CRISPR-Cas9 has the potential to upregulate the lysine reporter gene LYSA and increase the overall lysine content in rice.

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