Sticking to PIP2

نویسنده

  • Rabiya Tuma
چکیده

Tucker, and Edwin Chapman (University of Wisconsin, Madison, WI) find that PIP 2 is a plasma membrane dock for synaptotagmin-1 (syt), a transmembrane protein localized in secretory vesicle membranes, when calcium is absent. This dock may ensure speedy and directed fusion in response to calcium influx. The syt dock has two calcium-binding domains in its cytoplasmic region, called C 2 A and C 2 B. “What we discovered is that there are two modes of binding to PIP 2 mediated by the C 2 B domain of syt,” says Chapman. In the absence of calcium, syt binds PIP 2 weakly, lying on its side so that C 2 B contacts the PIP 2 head group. Once the C 2 A and C 2 B domains bind to calcium, however, the protein flips over to allow the opposite face of C 2 B to bind to PIP 2 . In this conformation, syt inserts membrane penetration prongs into the plasma membrane, potentially facilitating fusion with the secretory vesicle membrane and accelerating exocytosis. Thus, when calcium enters the cell, syt is already poised so that the first membrane C 2 B encounters is the plasma membrane. In other words, the syt-PIP 2 interaction essentially steers the synaptic vesicle to the plasma membrane in preparation for exocytosis.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effect of colloidal Particles associated with the liquid bridge in sticking during drying in Superheated Steam

It is very important in the design of a drying system is to evaluate sticking behaviour of the materials goes under drying. A new approach to the sticking issue is applied in this study by carrying out a sticking test for the liquid associated with the materials under study. It was found that the liquid bridge is responsible of the initial sticking of the materials to the contact surface and th...

متن کامل

Mathematical Modeling of the Differential Sticking Coefficient of Clay Drilling Fluids

The main objective of this work is to propose a mathematical model for the differential sticking coefficient of clayey drilling fluids with a lubricant as an additive and evaluate the influence of differential pressure and lubricant content on filter cake thickness and permeability. Tests were carried out on fluids composed of water and 4.86% of active bentonite clay prepared in Hamilton Beach ...

متن کامل

Inhibition of transient receptor potential A1 channel by phosphatidylinositol-4,5-bisphosphate.

Membrane phosphatidylinositol-4,5-bisphosphate (PIP2) is critical for the function of many transient receptor potential (TRP) ion channels. The role of PIP2 in TRPA1 function is not well known. The effect of PIP2 on TRPA1 was investigated by direct application of PIP2 and by using polylysine and PIP2 antibody that sequester PIP2. In inside-out patches from HeLa cells expressing mouse TRPA1, pol...

متن کامل

HERG K(+) channel activity is regulated by changes in phosphatidyl inositol 4,5-bisphosphate.

Autonomic stimulation controls heart rate and myocardial excitability and may underlie the precipitation of both acquired and hereditary arrhythmias. Changes in phosphatidyl inositol bisphosphate (PIP2) concentration results from activation of several muscarinic and adrenergic receptors. We sought to investigate whether PIP2 changes could alter HERG K(+) channel activity in a manner similar to ...

متن کامل

CAPS and Munc13 utilize distinct PIP2-linked mechanisms to promote vesicle exocytosis

Phosphoinositides provide compartment-specific signals for membrane trafficking. Plasma membrane phosphatidylinositol 4,5-bisphosphate (PIP2) is required for Ca(2+)-triggered vesicle exocytosis, but whether vesicles fuse into PIP2-rich membrane domains in live cells and whether PIP2 is metabolized during Ca(2+)-triggered fusion were unknown. Ca(2+)-dependent activator protein in secretion 1 (CA...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • The Journal of Cell Biology

دوره 164  شماره 

صفحات  -

تاریخ انتشار 2004