酵母蛋白分泌途径的研究
Randy Schekman (Berkeley) Part 1: Studying Protein Secretion in Yeast
Protein secretion is executed by a cellular pathway involving the delivery of membrane and soluble secretory proteins in vesicles that capture newly-synthesized proteins assembled in the endoplasmic reticulum (ER) and sorted in the Golgi apparatus. Vesicles fuse with the plasma membrane resulting in the discharge of soluble molecules to the cell exterior and integration of vesicle membrane proteins and lipids in the cell surface. Baker's yeast cells grow by vesicle fusion and secretion at the tip of the daughter bud. A genetic dissection of this process was performed with temperature sensitive conditional mutants blocked at one of several stations in the secretory pathway. See more athttp://www.ibioseminars.org
GE：CIPP蛋白纯化策略三部曲
小改变，大不同！主动出击，科学设计层析流程，革命性优化试验结果。本期网络讲堂我们将介绍CIPP：CIPP是经过证实的可靠蛋白纯化策略。我们将层析过程分为三个不同阶段：捕获（ Capture）、中度纯化（ intermediate Purification）、精细纯化（ Polishing），即CIPP。不同阶段目的是什么？不同阶段如何选择层析技术？各种层析技术如何衔接？我们都将一一阐述。
生物学中的蛋白质磷酸化 - Susan Taylor
In this lecture, I have given an overview of protein kinase structure and function using cyclic AMP dependent kinase (PKA) as a prototype for this enzyme superfamily. I have demonstrated what we have learned from the overall structural kinome which allows us to compare many protein kinases and also to appreciate how the highly regulated eukaryotic protein kinase has evolved. By comparing many protein kinase structures, we are beginning to elucidate general rules of architecture. In addition, I have attempted to illustrate how PKA is regulated by cAMP and how it is localized to specific macromolecular complexes through scaffold proteins.
蛋白激酶的结构 - Susan Taylor
In this lecture, I have given an overview of protein kinase structure and function using cyclic AMP dependent kinase (PKA) as a prototype for this enzyme superfamily. I have demonstrated what we have learned from the overall structural kinome which allows us to compare many protein kinases and also to appreciate how the highly regulated eukaryotic protein kinase has evolved. By comparing many protein kinase structures, we are beginning to elucidate general rules of architecture. In addition, I have attempted to illustrate how PKA is regulated by cAMP and how it is localized to specific macromolecular complexes through scaffold proteins.
蛋白激酶的调控与定位- Susan Taylor
In this lecture, I have given an overview of protein kinase structure and function using cyclic AMP dependent kinase (PKA) as a prototype for this enzyme superfamily. I have demonstrated what we have learned from the overall structural kinome which allows us to compare many protein kinases and also to appreciate how the highly regulated eukaryotic protein kinase has evolved. By comparing many protein kinase structures, we are beginning to elucidate general rules of architecture. In addition, I have attempted to illustrate how PKA is regulated by cAMP and how it is localized to specific macromolecular complexes through scaffold proteins.
肌动蛋白与细胞运动
Illustration of the role of actin polymers in cell movement and its conservation across species. Movies of moving neutrophils, amoeba and fish keratinocytes or skin cells. (3 movies)
蛋白质聚合产生的力
Models for how polymerization of actin filaments can produce enough force to push forward the leading edge of a cell at the speeds seen in living cells.
运动蛋白的介绍
Molecular motor proteins are fascinating enzymes that power much of the movement performed by living organisms. In the first part of this lecture, I will provide an overview of the motors that move along cytoskeletal tracks (kinesin and dynein which move along microtubules and myosin which moves along actin). The main focus of this lecture is on how motor proteins work. How does a nanoscale protein convert energy from ATP hydrolysis into unidirectional motion and force production? What tools do we have at our disposal to study them? The first part of the lecture will focus on these questions for kinesin (a microtubule-based motor) and myosin (an actin-based motor), since they have been the subject of extensive studies and good models for their mechanisms have emerged. I conclude by discussing the importance of understanding motor proteins for human disease, in particular illustrating a recent biotechnology effort from Cytokinetics, Inc. to develop drugs that activate cardiac myosins to improve cardiac contractility in patients suffering from heart failure. The first part of the lecture is directed to a general audience or a beginning graduate class.
In the second part of this lecture, I will discuss our laboratories current work on the mechanism of movement by dynein, a motor protein about which we still know very little. This is a research story in progress, where some advances have been made. However, much remains to be done in order to understand how this motor works.
The third (last) part of the lecture is on mitosis, the process by which chromosomes are aligned and then segregated during cell division. I will describe our efforts to find new proteins that are important for mitosis through a high throughput RNAi screen. I will discuss how we technically executed the screen and then focus on new proteins that are we discovered that are involved in generating the microtubules that compose the mitotic spindle. I also discuss the medical importance of studying mitosis, including the development of drugs targeted to mitotic motor proteins, which are currently undergoing testing in clinical trials.
单分子分析方法研究运动蛋白
Molecular motor proteins are fascinating enzymes that power much of the movement performed by living organisms. In the first part of this lecture, I will provide an overview of the motors that move along cytoskeletal tracks (kinesin and dynein which move along microtubules and myosin which moves along actin). The main focus of this lecture is on how motor proteins work. How does a nanoscale protein convert energy from ATP hydrolysis into unidirectional motion and force production? What tools do we have at our disposal to study them? The first part of the lecture will focus on these questions for kinesin (a microtubule-based motor) and myosin (an actin-based motor), since they have been the subject of extensive studies and good models for their mechanisms have emerged. I conclude by discussing the importance of understanding motor proteins for human disease, in particular illustrating a recent biotechnology effort from Cytokinetics, Inc. to develop drugs that activate cardiac myosins to improve cardiac contractility in patients suffering from heart failure. The first part of the lecture is directed to a general audience or a beginning graduate class.
In the second part of this lecture, I will discuss our laboratories current work on the mechanism of movement by dynein, a motor protein about which we still know very little. This is a research story in progress, where some advances have been made. However, much remains to be done in order to understand how this motor works.
The third (last) part of the lecture is on mitosis, the process by which chromosomes are aligned and then segregated during cell division. I will describe our efforts to find new proteins that are important for mitosis through a high throughput RNAi screen. I will discuss how we technically executed the screen and then focus on new proteins that are we discovered that are involved in generating the microtubules that compose the mitotic spindle. I also discuss the medical importance of studying mitosis, including the development of drugs targeted to mitotic motor proteins, which are currently undergoing testing in clinical trials.
GTP结合蛋白作为调节分子
When a growth factor binds to the plasma membrane of a quiescent cell, an intracellular signaling pathway is activated telling the cell to begin growing. A key molecule in this signaling pathway is the GTP-binding protein, or G-protein, Ras. Ras can act as an on-off switch telling the cell to grow or not. In its inactive form, Ras is bound to GDP while in its active form it is bound to GTP. This exchange of nucleotides is catalysed by guanine nucleotide-exchange-factors (GEFs). The return to the inactive state occurs through the GTPase reaction, which is accelerated by GTPase-activating proteins (GAPs). In Part 1 of his talk, Dr. Wittinghofer explains how solving the three-dimensional structure of Ras, and other G-proteins, allowed him to understand the conserved mechanism by which G-proteins can act as switches. The structure also identified domains unique to each G-protein that provide the specificity for downstream signals.